diff --git a/cmd/dep/integration_test.go b/cmd/dep/integration_test.go
index 5548cba516..cc9f959cc9 100644
--- a/cmd/dep/integration_test.go
+++ b/cmd/dep/integration_test.go
@@ -123,8 +123,12 @@ func testIntegration(name, relPath, wd string, run integration.RunFunc) func(t *
 		// Check error raised in final command
 		testCase.CompareError(err, testProj.GetStderr())
 
-		// Check output
-		testCase.CompareOutput(testProj.GetStdout())
+		if *test.UpdateGolden {
+			testCase.UpdateOutput(testProj.GetStdout())
+		} else {
+			// Check output
+			testCase.CompareOutput(testProj.GetStdout())
+		}
 
 		// Check vendor paths
 		testProj.CompareImportPaths()
diff --git a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-ignore/final/Gopkg.lock b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-ignore/final/Gopkg.lock
index 6dffa9af2d..1e637dd503 100644
--- a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-ignore/final/Gopkg.lock
+++ b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-ignore/final/Gopkg.lock
@@ -10,6 +10,6 @@
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "2381e3b3c6973c22f589e8f7cdf4fa63d009cfb815f86c7987a57b6b3661ebc3"
+  inputs-digest = "5210e61a67f6e64dabb1eb8f28df2dbeeedfca1588c102067a6ec8a35e0b15f9"
   solver-name = "gps-cdcl"
   solver-version = 1
diff --git a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-ignore/stdout.txt b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-ignore/stdout.txt
new file mode 100644
index 0000000000..74542e41e5
--- /dev/null
+++ b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-ignore/stdout.txt
@@ -0,0 +1,11 @@
+-CONSTRAINTS-
+github.com/sdboyer/deptest
+b-master
+-IMPORTS/REQS-
+github.com/sdboyer/deptest
+-IGNORES-
+-OVERRIDES-
+-ANALYZER-
+dep
+1
+
diff --git a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-ignore/testcase.json b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-ignore/testcase.json
index 729de9d0f4..5641e85616 100644
--- a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-ignore/testcase.json
+++ b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-ignore/testcase.json
@@ -1,6 +1,7 @@
 {
   "commands": [
-    ["ensure"]
+    ["ensure"],
+    ["hash-inputs"]
   ],
   "error-expected": "",
   "vendor-final": [
diff --git a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/final/Gopkg.lock b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/final/Gopkg.lock
new file mode 100644
index 0000000000..53e42dcc48
--- /dev/null
+++ b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/final/Gopkg.lock
@@ -0,0 +1,9 @@
+# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
+
+
+[solve-meta]
+  analyzer-name = "dep"
+  analyzer-version = 1
+  inputs-digest = "b02b7a80e20404724ba5dbffab28e772017b03800916327f58bff0da86071b6a"
+  solver-name = "gps-cdcl"
+  solver-version = 1
diff --git a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/final/Gopkg.toml b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/final/Gopkg.toml
new file mode 100644
index 0000000000..f54b63d573
--- /dev/null
+++ b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/final/Gopkg.toml
@@ -0,0 +1 @@
+ignored = ["github.com/sdboyer/deptest*", "github.com/golang/notexist/samples*"]
diff --git a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/Gopkg.lock b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/Gopkg.lock
new file mode 100644
index 0000000000..bef2d0092e
--- /dev/null
+++ b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/Gopkg.lock
@@ -0,0 +1,9 @@
+# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
+
+
+[solve-meta]
+  analyzer-name = "dep"
+  analyzer-version = 1
+  inputs-digest = "ab4fef131ee828e96ba67d31a7d690bd5f2f42040c6766b1b12fe856f87e0ff7"
+  solver-name = "gps-cdcl"
+  solver-version = 1
diff --git a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/Gopkg.toml b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/Gopkg.toml
new file mode 100644
index 0000000000..f54b63d573
--- /dev/null
+++ b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/Gopkg.toml
@@ -0,0 +1 @@
+ignored = ["github.com/sdboyer/deptest*", "github.com/golang/notexist/samples*"]
diff --git a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/main.go b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/main.go
new file mode 100644
index 0000000000..e23fcf34c5
--- /dev/null
+++ b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/main.go
@@ -0,0 +1,12 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	_ "github.com/sdboyer/deptest"
+)
+
+func main() {
+}
diff --git a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/samples/samples.go b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/samples/samples.go
new file mode 100644
index 0000000000..d07de170f7
--- /dev/null
+++ b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/samples/samples.go
@@ -0,0 +1,7 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package samples
+
+import _ "github.com/sdboyer/deptestdos"
diff --git a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/samples/subsamples/subsamples.go b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/samples/subsamples/subsamples.go
new file mode 100644
index 0000000000..5136538e6d
--- /dev/null
+++ b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/initial/samples/subsamples/subsamples.go
@@ -0,0 +1,7 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package subsamples
+
+import _ "github.com/sdboyer/dep-test"
diff --git a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/stdout.txt b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/stdout.txt
new file mode 100644
index 0000000000..a273de0e56
--- /dev/null
+++ b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/stdout.txt
@@ -0,0 +1,9 @@
+-CONSTRAINTS-
+-IMPORTS/REQS-
+-IGNORES-
+github.com/sdboyer/deptest*
+-OVERRIDES-
+-ANALYZER-
+dep
+1
+
diff --git a/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/testcase.json b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/testcase.json
new file mode 100644
index 0000000000..4f16d1c611
--- /dev/null
+++ b/cmd/dep/testdata/harness_tests/ensure/pkg-ignored/wildcard-other-root/testcase.json
@@ -0,0 +1,8 @@
+{
+  "commands": [
+    ["ensure"],
+    ["hash-inputs"]
+  ],
+  "error-expected": "",
+  "vendor-final": []
+}
diff --git a/cmd/dep/testdata/harness_tests/init/glide/case1/final/Gopkg.toml b/cmd/dep/testdata/harness_tests/init/glide/case1/final/Gopkg.toml
index f9d63b74dc..ba8a4248b5 100644
--- a/cmd/dep/testdata/harness_tests/init/glide/case1/final/Gopkg.toml
+++ b/cmd/dep/testdata/harness_tests/init/glide/case1/final/Gopkg.toml
@@ -1,4 +1,4 @@
-ignored = ["github.com/sdboyer/dep-test","github.com/golang/notexist/samples"]
+ignored = ["github.com/golang/notexist/samples","github.com/sdboyer/dep-test"]
 
 [[constraint]]
   name = "github.com/carolynvs/deptest-subpkg"
diff --git a/internal/gps/hash.go b/internal/gps/hash.go
index be35a17a2d..556933bcf3 100644
--- a/internal/gps/hash.go
+++ b/internal/gps/hash.go
@@ -13,8 +13,6 @@ import (
 	"strings"
 )
 
-const wcIgnoreSuffix = "*"
-
 // string headers used to demarcate sections in hash input creation
 const (
 	hhConstraints = "-CONSTRAINTS-"
@@ -81,30 +79,16 @@ func (s *solver) writeHashingInputs(w io.Writer) {
 	// those will have already been implicitly incorporated by the import
 	// lister.
 	writeString(hhIgnores)
-	ig := make([]string, 0, len(s.rd.ig))
-	for pkg := range s.rd.ig {
-		// Skip wildcard ignore. They are handled separately below.
-		if strings.HasSuffix(pkg, wcIgnoreSuffix) {
-			continue
-		}
-
-		if !strings.HasPrefix(pkg, s.rd.rpt.ImportRoot) || !isPathPrefixOrEqual(s.rd.rpt.ImportRoot, pkg) {
-			ig = append(ig, pkg)
-		}
-	}
-
-	// Add wildcard ignores to ignore list.
-	if s.rd.igpfx != nil {
-		s.rd.igpfx.Walk(func(s string, v interface{}) bool {
-			ig = append(ig, s+"*")
-			return false
-		})
-	}
 
+	ig := s.rd.ir.ToSlice()
 	sort.Strings(ig)
-
 	for _, igp := range ig {
-		writeString(igp)
+		// Typical prefix comparison checks will erroneously fail if the wildcard
+		// is present. Trim it off, if present.
+		tigp := strings.TrimSuffix(igp, "*")
+		if !strings.HasPrefix(tigp, s.rd.rpt.ImportRoot) || !isPathPrefixOrEqual(s.rd.rpt.ImportRoot, tigp) {
+			writeString(igp)
+		}
 	}
 
 	// Overrides *also* need their own special entry distinct from basic
diff --git a/internal/gps/hash_test.go b/internal/gps/hash_test.go
index aa5113962f..52898e50ae 100644
--- a/internal/gps/hash_test.go
+++ b/internal/gps/hash_test.go
@@ -11,6 +11,8 @@ import (
 	"strings"
 	"testing"
 	"text/tabwriter"
+
+	"github.com/golang/dep/internal/gps/pkgtree"
 )
 
 func TestHashInputs(t *testing.T) {
@@ -64,10 +66,7 @@ func TestHashInputsReqsIgs(t *testing.T) {
 	fix := basicFixtures["shared dependency with overlapping constraints"]
 
 	rm := fix.rootmanifest().(simpleRootManifest).dup()
-	rm.ig = map[string]bool{
-		"foo": true,
-		"bar": true,
-	}
+	rm.ig = pkgtree.NewIgnoredRuleset([]string{"foo", "bar"})
 
 	params := SolveParameters{
 		RootDir:         string(fix.ds[0].n),
@@ -611,7 +610,7 @@ func TestHashInputsIneffectualWildcardIgs(t *testing.T) {
 
 	cases := []struct {
 		name      string
-		ignoreMap map[string]bool
+		ignoreMap []string
 		elems     []string
 	}{
 		{
@@ -634,10 +633,10 @@ func TestHashInputsIneffectualWildcardIgs(t *testing.T) {
 		},
 		{
 			name: "different wildcard ignores",
-			ignoreMap: map[string]bool{
-				"foobar*":    true,
-				"foobarbaz*": true,
-				"foozapbar*": true,
+			ignoreMap: []string{
+				"foobar*",
+				"foobarbaz*",
+				"foozapbar*",
 			},
 			elems: []string{
 				hhConstraints,
@@ -662,7 +661,7 @@ func TestHashInputsIneffectualWildcardIgs(t *testing.T) {
 	for _, c := range cases {
 		t.Run(c.name, func(t *testing.T) {
 
-			rm.ig = c.ignoreMap
+			rm.ig = pkgtree.NewIgnoredRuleset(c.ignoreMap)
 
 			params.Manifest = rm
 
diff --git a/internal/gps/manifest.go b/internal/gps/manifest.go
index 625088f94b..e13ff95971 100644
--- a/internal/gps/manifest.go
+++ b/internal/gps/manifest.go
@@ -4,6 +4,8 @@
 
 package gps
 
+import "github.com/golang/dep/internal/gps/pkgtree"
+
 // Manifest represents manifest-type data for a project at a particular version.
 // The constraints expressed in a manifest determine the set of versions that
 // are acceptable to try for a given project.
@@ -36,14 +38,15 @@ type RootManifest interface {
 	// them can harm the ecosystem as a whole.
 	Overrides() ProjectConstraints
 
-	// IngoredPackages returns a set of import paths to ignore. These import
-	// paths can be within the root project, or part of other projects. Ignoring
-	// a package means that both it and its (unique) imports will be disregarded
-	// by all relevant solver operations.
+	// IngoredPackages returns a pkgtree.IgnoredRuleset, which comprises a set
+	// of import paths, or import path patterns, that are to be ignored during
+	// solving. These ignored import paths can be within the root project, or
+	// part of other projects. Ignoring a package means that both it and its
+	// (unique) imports will be disregarded by all relevant solver operations.
 	//
 	// It is an error to include a package in both the ignored and required
 	// sets.
-	IgnoredPackages() map[string]bool
+	IgnoredPackages() *pkgtree.IgnoredRuleset
 
 	// RequiredPackages returns a set of import paths to require. These packages
 	// are required to be present in any solution. The list can include main
@@ -76,8 +79,9 @@ func (m SimpleManifest) DependencyConstraints() ProjectConstraints {
 // simpleRootManifest exists so that we have a safe value to swap into solver
 // params when a nil Manifest is provided.
 type simpleRootManifest struct {
-	c, ovr  ProjectConstraints
-	ig, req map[string]bool
+	c, ovr ProjectConstraints
+	ig     *pkgtree.IgnoredRuleset
+	req    map[string]bool
 }
 
 func (m simpleRootManifest) DependencyConstraints() ProjectConstraints {
@@ -86,7 +90,7 @@ func (m simpleRootManifest) DependencyConstraints() ProjectConstraints {
 func (m simpleRootManifest) Overrides() ProjectConstraints {
 	return m.ovr
 }
-func (m simpleRootManifest) IgnoredPackages() map[string]bool {
+func (m simpleRootManifest) IgnoredPackages() *pkgtree.IgnoredRuleset {
 	return m.ig
 }
 func (m simpleRootManifest) RequiredPackages() map[string]bool {
@@ -96,7 +100,6 @@ func (m simpleRootManifest) dup() simpleRootManifest {
 	m2 := simpleRootManifest{
 		c:   make(ProjectConstraints, len(m.c)),
 		ovr: make(ProjectConstraints, len(m.ovr)),
-		ig:  make(map[string]bool, len(m.ig)),
 		req: make(map[string]bool, len(m.req)),
 	}
 
@@ -106,13 +109,13 @@ func (m simpleRootManifest) dup() simpleRootManifest {
 	for k, v := range m.ovr {
 		m2.ovr[k] = v
 	}
-	for k, v := range m.ig {
-		m2.ig[k] = v
-	}
 	for k, v := range m.req {
 		m2.req[k] = v
 	}
 
+	// IgnoredRulesets are immutable, and safe to reuse.
+	m2.ig = m.ig
+
 	return m2
 }
 
diff --git a/internal/gps/pkgtree/pkgtree.go b/internal/gps/pkgtree/pkgtree.go
index fd4d10b7bc..78be8b42f4 100644
--- a/internal/gps/pkgtree/pkgtree.go
+++ b/internal/gps/pkgtree/pkgtree.go
@@ -22,9 +22,6 @@ import (
 	"github.com/armon/go-radix"
 )
 
-// wildcard ignore suffix
-const wcIgnoreSuffix = "*"
-
 // Package represents a Go package. It contains a subset of the information
 // go/build.Package does.
 type Package struct {
@@ -550,14 +547,7 @@ type PackageTree struct {
 // 	"A": []string{},
 // 	"A/bar": []string{"B/baz"},
 //  }
-func (t PackageTree) ToReachMap(main, tests, backprop bool, ignore map[string]bool) (ReachMap, map[string]*ProblemImportError) {
-	if ignore == nil {
-		ignore = make(map[string]bool)
-	}
-
-	// Radix tree for ignore prefixes.
-	xt := CreateIgnorePrefixTree(ignore)
-
+func (t PackageTree) ToReachMap(main, tests, backprop bool, ignore *IgnoredRuleset) (ReachMap, map[string]*ProblemImportError) {
 	// world's simplest adjacency list
 	workmap := make(map[string]wm)
 
@@ -576,18 +566,10 @@ func (t PackageTree) ToReachMap(main, tests, backprop bool, ignore map[string]bo
 			continue
 		}
 		// Skip ignored packages
-		if ignore[ip] {
+		if ignore.IsIgnored(ip) {
 			continue
 		}
 
-		if xt != nil {
-			// Skip ignored packages prefix matches
-			_, _, ok := xt.LongestPrefix(ip)
-			if ok {
-				continue
-			}
-		}
-
 		// TODO (kris-nova) Disable to get staticcheck passing
 		//imps = imps[:0]
 
@@ -605,7 +587,7 @@ func (t PackageTree) ToReachMap(main, tests, backprop bool, ignore map[string]bo
 		// For each import, decide whether it should be ignored, or if it
 		// belongs in the external or internal imports list.
 		for _, imp := range imps {
-			if ignore[imp] || imp == "." {
+			if ignore.IsIgnored(imp) || imp == "." {
 				continue
 			}
 
@@ -1043,41 +1025,101 @@ func uniq(a []string) []string {
 	return a[:i]
 }
 
-// CreateIgnorePrefixTree takes a set of strings to be ignored and returns a
-// trie consisting of strings prefixed with wildcard ignore suffix (*).
-func CreateIgnorePrefixTree(ig map[string]bool) *radix.Tree {
-	var xt *radix.Tree
+// IgnoredRuleset comprises a set of rules for ignoring import paths. It can
+// manage both literal and prefix-wildcard matches.
+type IgnoredRuleset struct {
+	t *radix.Tree
+}
+
+// NewIgnoredRuleset processes a set of strings into an IgnoredRuleset. Strings
+// that end in "*" are treated as wildcards, where any import path with a
+// matching prefix will be ignored. IgnoredRulesets are immutable once created.
+//
+// Duplicate and redundant (i.e. a literal path that has a prefix of a wildcard
+// path) declarations are discarded. Consequently, it is possible that the
+// returned IgnoredRuleset may have a smaller Len() than the input slice.
+func NewIgnoredRuleset(ig []string) *IgnoredRuleset {
+	if len(ig) == 0 {
+		return &IgnoredRuleset{}
+	}
 
-	// Create a sorted list of all the ignores to have a proper order in
-	// ignores parsing.
-	sortedIgnores := make([]string, len(ig))
-	for k := range ig {
-		sortedIgnores = append(sortedIgnores, k)
+	ir := &IgnoredRuleset{
+		t: radix.New(),
 	}
-	sort.Strings(sortedIgnores)
 
-	for _, i := range sortedIgnores {
-		// Skip global ignore.
-		if i == "*" {
+	// Sort the list of all the ignores in order to ensure that wildcard
+	// precedence is recorded correctly in the trie.
+	sort.Strings(ig)
+	for _, i := range ig {
+		// Skip global ignore and empty string.
+		if i == "*" || i == "" {
 			continue
 		}
 
-		// Check if it's a recursive ignore.
-		if strings.HasSuffix(i, wcIgnoreSuffix) {
-			// Create trie if it doesn't exists.
-			if xt == nil {
-				xt = radix.New()
-			}
+		_, wildi, has := ir.t.LongestPrefix(i)
+		// We may not always have a value here, but if we do, then it's a bool.
+		wild, _ := wildi.(bool)
+		// Check if it's a wildcard ignore.
+		if strings.HasSuffix(i, "*") {
 			// Check if it is ineffectual.
-			_, _, ok := xt.LongestPrefix(i)
-			if ok {
+			if has && wild {
 				// Skip ineffectual wildcard ignore.
 				continue
 			}
 			// Create the ignore prefix and insert in the radix tree.
-			xt.Insert(i[:len(i)-len(wcIgnoreSuffix)], true)
+			ir.t.Insert(i[:len(i)-1], true)
+		} else if !has || !wild {
+			ir.t.Insert(i, false)
 		}
 	}
 
-	return xt
+	if ir.t.Len() == 0 {
+		ir.t = nil
+	}
+
+	return ir
+}
+
+// IsIgnored indicates whether the provided path should be ignored, according to
+// the ruleset.
+func (ir *IgnoredRuleset) IsIgnored(path string) bool {
+	if path == "" || ir == nil || ir.t == nil {
+		return false
+	}
+
+	prefix, wildi, has := ir.t.LongestPrefix(path)
+	return has && (wildi.(bool) || path == prefix)
+}
+
+// Len indicates the number of rules in the ruleset.
+func (ir *IgnoredRuleset) Len() int {
+	if ir == nil || ir.t == nil {
+		return 0
+	}
+
+	return ir.t.Len()
+}
+
+// ToSlice converts the contents of the IgnoredRuleset to a string slice.
+//
+// This operation is symmetrically dual to NewIgnoredRuleset.
+func (ir *IgnoredRuleset) ToSlice() []string {
+	irlen := ir.Len()
+	if irlen == 0 {
+		return nil
+	}
+
+	items := make([]string, 0, irlen)
+	ir.t.Walk(func(s string, v interface{}) bool {
+		if s != "" {
+			if v.(bool) {
+				items = append(items, s+"*")
+			} else {
+				items = append(items, s)
+			}
+		}
+		return false
+	})
+
+	return items
 }
diff --git a/internal/gps/pkgtree/pkgtree_test.go b/internal/gps/pkgtree/pkgtree_test.go
index 554d9cac0e..bb97c11c6b 100644
--- a/internal/gps/pkgtree/pkgtree_test.go
+++ b/internal/gps/pkgtree/pkgtree_test.go
@@ -1524,10 +1524,10 @@ func TestToReachMap(t *testing.T) {
 	var want ReachMap
 	var name string
 	var main, tests bool
-	var ignore map[string]bool
+	var ignore []string
 
 	validate := func() {
-		got, em := vptree.ToReachMap(main, tests, true, ignore)
+		got, em := vptree.ToReachMap(main, tests, true, NewIgnoredRuleset(ignore))
 		if len(em) != 0 {
 			t.Errorf("Should not have any error packages from ToReachMap, got %s", em)
 		}
@@ -1687,9 +1687,7 @@ func TestToReachMap(t *testing.T) {
 
 	// ignoring the "varied" pkg has same effect as disabling main pkgs
 	name = "ignore root"
-	ignore = map[string]bool{
-		b(""): true,
-	}
+	ignore = []string{b("")}
 	main = true
 	validate()
 
@@ -1723,9 +1721,7 @@ func TestToReachMap(t *testing.T) {
 	// now, the fun stuff. punch a hole in the middle by cutting out
 	// varied/simple
 	name = "ignore varied/simple"
-	ignore = map[string]bool{
-		b("simple"): true,
-	}
+	ignore = []string{b("simple")}
 	except(
 		// root pkg loses on everything in varied/simple/another
 		// FIXME this is a bit odd, but should probably exclude m1p as well,
@@ -1738,9 +1734,9 @@ func TestToReachMap(t *testing.T) {
 
 	// widen the hole by excluding otherpath
 	name = "ignore varied/{otherpath,simple}"
-	ignore = map[string]bool{
-		b("otherpath"): true,
-		b("simple"):    true,
+	ignore = []string{
+		b("otherpath"),
+		b("simple"),
 	}
 	except(
 		// root pkg loses on everything in varied/simple/another and varied/m1p
@@ -1752,7 +1748,7 @@ func TestToReachMap(t *testing.T) {
 
 	// remove namemismatch, though we're mostly beating a dead horse now
 	name = "ignore varied/{otherpath,simple,namemismatch}"
-	ignore[b("namemismatch")] = true
+	ignore = append(ignore, b("namemismatch"))
 	except(
 		// root pkg loses on everything in varied/simple/another and varied/m1p
 		bl("", "simple", "simple/another", "m1p", "otherpath", "namemismatch")+" hash encoding/binary go/parser github.com/golang/dep/internal/gps sort os github.com/Masterminds/semver",
@@ -1851,9 +1847,9 @@ func TestFlattenReachMap(t *testing.T) {
 			isStdLibFn: nil,
 			main:       true,
 			tests:      true,
-			ignore: map[string]bool{
-				"nomatch": true,
-			},
+			ignore: NewIgnoredRuleset([]string{
+				"nomatch",
+			}),
 		},
 		// should have the same effect as ignoring main
 		{
@@ -1862,9 +1858,9 @@ func TestFlattenReachMap(t *testing.T) {
 			isStdLibFn: nil,
 			main:       true,
 			tests:      true,
-			ignore: map[string]bool{
-				"github.com/example/varied": true,
-			},
+			ignore: NewIgnoredRuleset([]string{
+				"github.com/example/varied",
+			}),
 		},
 		// now drop a more interesting one
 		// we get github.com/golang/dep/internal/gps from m1p, too, so it should still be there
@@ -1874,9 +1870,9 @@ func TestFlattenReachMap(t *testing.T) {
 			isStdLibFn: nil,
 			main:       true,
 			tests:      true,
-			ignore: map[string]bool{
-				"github.com/example/varied/simple": true,
-			},
+			ignore: NewIgnoredRuleset([]string{
+				"github.com/example/varied/simple",
+			}),
 		},
 		// now drop two
 		{
@@ -1885,10 +1881,10 @@ func TestFlattenReachMap(t *testing.T) {
 			isStdLibFn: nil,
 			main:       true,
 			tests:      true,
-			ignore: map[string]bool{
-				"github.com/example/varied/simple":       true,
-				"github.com/example/varied/namemismatch": true,
-			},
+			ignore: NewIgnoredRuleset([]string{
+				"github.com/example/varied/simple",
+				"github.com/example/varied/namemismatch",
+			}),
 		},
 		// make sure tests and main play nice with ignore
 		{
@@ -1897,10 +1893,10 @@ func TestFlattenReachMap(t *testing.T) {
 			isStdLibFn: nil,
 			main:       true,
 			tests:      false,
-			ignore: map[string]bool{
-				"github.com/example/varied/simple":       true,
-				"github.com/example/varied/namemismatch": true,
-			},
+			ignore: NewIgnoredRuleset([]string{
+				"github.com/example/varied/simple",
+				"github.com/example/varied/namemismatch",
+			}),
 		},
 		{
 			name:       "ignore simple and namemismatch, and no main",
@@ -1908,10 +1904,10 @@ func TestFlattenReachMap(t *testing.T) {
 			isStdLibFn: nil,
 			main:       false,
 			tests:      true,
-			ignore: map[string]bool{
-				"github.com/example/varied/simple":       true,
-				"github.com/example/varied/namemismatch": true,
-			},
+			ignore: NewIgnoredRuleset([]string{
+				"github.com/example/varied/simple",
+				"github.com/example/varied/namemismatch",
+			}),
 		},
 		{
 			name:       "ignore simple and namemismatch, and no main or tests",
@@ -1919,10 +1915,10 @@ func TestFlattenReachMap(t *testing.T) {
 			isStdLibFn: nil,
 			main:       false,
 			tests:      false,
-			ignore: map[string]bool{
-				"github.com/example/varied/simple":       true,
-				"github.com/example/varied/namemismatch": true,
-			},
+			ignore: NewIgnoredRuleset([]string{
+				"github.com/example/varied/simple",
+				"github.com/example/varied/namemismatch",
+			}),
 		},
 		// ignore two that should knock out gps
 		{
@@ -1931,10 +1927,10 @@ func TestFlattenReachMap(t *testing.T) {
 			isStdLibFn: nil,
 			main:       true,
 			tests:      true,
-			ignore: map[string]bool{
-				"github.com/example/varied/simple": true,
-				"github.com/example/varied/m1p":    true,
-			},
+			ignore: NewIgnoredRuleset([]string{
+				"github.com/example/varied/simple",
+				"github.com/example/varied/m1p",
+			}),
 		},
 		// finally, directly ignore some external packages
 		{
@@ -1943,11 +1939,11 @@ func TestFlattenReachMap(t *testing.T) {
 			isStdLibFn: nil,
 			main:       true,
 			tests:      true,
-			ignore: map[string]bool{
-				"github.com/golang/dep/internal/gps": true,
-				"go/parser":                          true,
-				"sort":                               true,
-			},
+			ignore: NewIgnoredRuleset([]string{
+				"github.com/golang/dep/internal/gps",
+				"go/parser",
+				"sort",
+			}),
 		},
 	} {
 		t.Run(testCase.name, testFlattenReachMap(&vptree, testCase))
@@ -1971,7 +1967,7 @@ func TestFlattenReachMap(t *testing.T) {
 type flattenReachMapCase struct {
 	expect      []string
 	name        string
-	ignore      map[string]bool
+	ignore      *IgnoredRuleset
 	main, tests bool
 	isStdLibFn  func(string) bool
 }
@@ -2039,91 +2035,199 @@ func getTestdataRootDir(t *testing.T) string {
 	return filepath.Join(cwd, "..", "_testdata")
 }
 
-func TestCreateIgnorePrefixTree(t *testing.T) {
+func TestIgnoredRuleset(t *testing.T) {
+	type tfixm []struct {
+		path string
+		wild bool
+	}
 	cases := []struct {
-		name          string
-		ignoreMap     map[string]bool
-		wantInTree    []string
-		notWantInTree []string
-		wantNilTree   bool
+		name            string
+		inputs          []string
+		wantInTree      tfixm
+		wantEmptyTree   bool
+		shouldIgnore    []string
+		shouldNotIgnore []string
 	}{
 		{
-			name:        "empty ignore",
-			wantNilTree: true,
+			name:          "only skip global ignore",
+			inputs:        []string{"*"},
+			wantEmptyTree: true,
 		},
 		{
 			name: "ignores without ignore suffix",
-			ignoreMap: map[string]bool{
-				"x/y/z":   true,
-				"*a/b/c":  true,
-				"gophers": true,
+			inputs: []string{
+				"x/y/z",
+				"*a/b/c",
+				"gophers",
+			},
+			wantInTree: tfixm{
+				{path: "x/y/z", wild: false},
+				{path: "*a/b/c", wild: false},
+				{path: "gophers", wild: false},
+			},
+			shouldIgnore: []string{
+				"x/y/z",
+				"gophers",
+			},
+			shouldNotIgnore: []string{
+				"x/y/z/q",
+				"x/y",
+				"gopher",
+				"gopherss",
 			},
-			wantNilTree: true,
 		},
 		{
 			name: "ignores with ignore suffix",
-			ignoreMap: map[string]bool{
-				"x/y/z*":  true,
-				"a/b/c":   true,
-				"gophers": true,
+			inputs: []string{
+				"x/y/z*",
+				"a/b/c",
+				"gophers",
+			},
+			wantInTree: tfixm{
+				{path: "x/y/z", wild: true},
+				{path: "a/b/c", wild: false},
+				{path: "gophers", wild: false},
+			},
+			shouldIgnore: []string{
+				"x/y/z",
+				"x/y/zz",
+				"x/y/z/",
+				"x/y/z/q",
+			},
+			shouldNotIgnore: []string{
+				"x/y",
+				"gopher",
 			},
-			wantInTree:    []string{"x/y/z"},
-			notWantInTree: []string{"a/b/c", "gophers"},
-		},
-		{
-			name:        "only skip global ignore",
-			ignoreMap:   map[string]bool{"*": true},
-			wantNilTree: true,
 		},
 		{
 			name: "global ignore with other strings",
-			ignoreMap: map[string]bool{
-				"*":        true,
-				"gophers*": true,
-				"x/y/z*":   true,
-				"a/b/c":    true,
-			},
-			wantInTree:    []string{"gophers", "x/y/z"},
-			notWantInTree: []string{"*", "a/b/c"},
+			inputs: []string{
+				"*",
+				"gophers*",
+				"x/y/z*",
+				"a/b/c",
+			},
+			wantInTree: tfixm{
+				{path: "x/y/z", wild: true},
+				{path: "a/b/c", wild: false},
+				{path: "gophers", wild: true},
+			},
+			shouldIgnore: []string{
+				"x/y/z",
+				"x/y/z/",
+				"x/y/z/q",
+				"gophers",
+				"gopherss",
+				"gophers/foo",
+			},
+			shouldNotIgnore: []string{
+				"x/y",
+				"gopher",
+			},
 		},
 		{
 			name: "ineffectual ignore with wildcard",
-			ignoreMap: map[string]bool{
-				"a/b*":    true,
-				"a/b/c*":  true,
-				"a/b/x/y": true,
-				"a/c*":    true,
-			},
-			wantInTree:    []string{"a/b", "a/c"},
-			notWantInTree: []string{"a/b/c", "a/b/x/y"},
+			inputs: []string{
+				"a/b*",
+				"a/b/c*",
+				"a/b/x/y",
+				"a/c*",
+			},
+			wantInTree: tfixm{
+				{path: "a/c", wild: true},
+				{path: "a/b", wild: true},
+			},
+			shouldIgnore: []string{
+				"a/cb",
+			},
+			shouldNotIgnore: []string{
+				"a/",
+				"a/d",
+			},
+		},
+		{
+			name: "same path with and without wildcard",
+			inputs: []string{
+				"a/b*",
+				"a/b",
+			},
+			wantInTree: tfixm{
+				{path: "a/b", wild: true},
+			},
+			shouldIgnore: []string{
+				"a/b",
+				"a/bb",
+			},
+			shouldNotIgnore: []string{
+				"a/",
+				"a/d",
+			},
+		},
+		{
+			name: "empty paths",
+			inputs: []string{
+				"",
+				"a/b*",
+			},
+			wantInTree: tfixm{
+				{path: "a/b", wild: true},
+			},
+			shouldNotIgnore: []string{
+				"",
+			},
+		},
+		{
+			name: "single wildcard",
+			inputs: []string{
+				"a/b*",
+			},
+			wantInTree: tfixm{
+				{path: "a/b", wild: true},
+			},
+			shouldIgnore: []string{
+				"a/b/c",
+			},
 		},
 	}
 
 	for _, c := range cases {
-		t.Run(c.name, func(t *testing.T) {
-			gotTree := CreateIgnorePrefixTree(c.ignoreMap)
+		igm := NewIgnoredRuleset(c.inputs)
+		f := func(t *testing.T) {
 
-			if c.wantNilTree {
-				if gotTree != nil {
-					t.Fatalf("expected nil tree, got non-nil tree")
+			if c.wantEmptyTree {
+				if igm.Len() != 0 {
+					t.Fatalf("wanted empty tree, but had %v elements", igm.Len())
 				}
 			}
 
 			// Check if the wildcard suffix ignores are in the tree.
 			for _, p := range c.wantInTree {
-				_, has := gotTree.Get(p)
+				wildi, has := igm.t.Get(p.path)
 				if !has {
-					t.Fatalf("expected %q to be in the tree", p)
+					t.Fatalf("expected %q to be in the tree", p.path)
+				} else if wildi.(bool) != p.wild {
+					if p.wild {
+						t.Fatalf("expected %q to be a wildcard matcher, but it was not", p.path)
+					} else {
+						t.Fatalf("expected %q not to be a wildcard matcher, but it was", p.path)
+					}
 				}
 			}
 
-			// Check if non-wildcard suffix ignores are not in the tree.
-			for _, p := range c.notWantInTree {
-				_, has := gotTree.Get(p)
-				if has {
-					t.Fatalf("expected %q to not be in the tree", p)
+			for _, p := range c.shouldIgnore {
+				if !igm.IsIgnored(p) {
+					t.Fatalf("%q should be ignored, but it was not", p)
 				}
 			}
-		})
+			for _, p := range c.shouldNotIgnore {
+				if igm.IsIgnored(p) {
+					t.Fatalf("%q should not be ignored, but it was", p)
+				}
+			}
+		}
+		t.Run(c.name, f)
+
+		igm = NewIgnoredRuleset(igm.ToSlice())
+		t.Run(c.name+"/inandout", f)
 	}
 }
diff --git a/internal/gps/rootdata.go b/internal/gps/rootdata.go
index eeae1c04f8..22e7fecad1 100644
--- a/internal/gps/rootdata.go
+++ b/internal/gps/rootdata.go
@@ -17,11 +17,8 @@ type rootdata struct {
 	// Path to the root of the project on which gps is operating.
 	dir string
 
-	// Map of packages to ignore.
-	ig map[string]bool
-
-	// Radix tree of ignore prefixes.
-	igpfx *radix.Tree
+	// Ruleset for ignored import paths.
+	ir *pkgtree.IgnoredRuleset
 
 	// Map of packages to require.
 	req map[string]bool
@@ -57,7 +54,7 @@ type rootdata struct {
 // Ignores and requires are taken into consideration, stdlib is excluded, and
 // errors within the local set of package are not backpropagated.
 func (rd rootdata) externalImportList(stdLibFn func(string) bool) []string {
-	rm, _ := rd.rpt.ToReachMap(true, true, false, rd.ig)
+	rm, _ := rd.rpt.ToReachMap(true, true, false, rd.ir)
 	reach := rm.FlattenFn(stdLibFn)
 
 	// If there are any requires, slide them into the reach list, as well.
@@ -194,7 +191,7 @@ func (rd rootdata) rootAtom() atomWithPackages {
 
 	list := make([]string, 0, len(rd.rpt.Packages))
 	for path, pkg := range rd.rpt.Packages {
-		if pkg.Err != nil && !rd.ig[path] {
+		if pkg.Err != nil && !rd.ir.IsIgnored(path) {
 			list = append(list, path)
 		}
 	}
@@ -205,20 +202,3 @@ func (rd rootdata) rootAtom() atomWithPackages {
 		pl: list,
 	}
 }
-
-// isIgnored checks if a given path is ignored, comparing with the list of
-// ignore packages and ignore prefixes.
-func (rd rootdata) isIgnored(path string) bool {
-	// Check if the path is present in ignore packages.
-	if rd.ig[path] {
-		return true
-	}
-
-	if rd.igpfx != nil {
-		// Check if the path matches any of the ignore prefixes.
-		_, _, ok := rd.igpfx.LongestPrefix(path)
-		return ok
-	}
-
-	return false
-}
diff --git a/internal/gps/rootdata_test.go b/internal/gps/rootdata_test.go
index 8578c12394..7890669b8b 100644
--- a/internal/gps/rootdata_test.go
+++ b/internal/gps/rootdata_test.go
@@ -58,7 +58,7 @@ func TestRootdataExternalImports(t *testing.T) {
 	// Add an ignore, but not on the required path (Prepare makes that
 	// combination impossible)
 
-	rd.ig["b"] = true
+	rd.ir = pkgtree.NewIgnoredRuleset([]string{"b"})
 	want = []string{"a", "c"}
 	got = rd.externalImportList(params.stdLibFn)
 	if !reflect.DeepEqual(want, got) {
@@ -194,7 +194,7 @@ func TestGetApplicableConstraints(t *testing.T) {
 			// violate the principle of least surprise?
 			name: "ignore imported and overridden pkg",
 			mut: func() {
-				rd.ig["d"] = true
+				rd.ir = pkgtree.NewIgnoredRuleset([]string{"d"})
 			},
 			result: []workingConstraint{
 				{
@@ -224,58 +224,3 @@ func TestGetApplicableConstraints(t *testing.T) {
 		})
 	}
 }
-
-func TestIsIgnored(t *testing.T) {
-	cases := []struct {
-		name           string
-		ignorePkgs     map[string]bool
-		wantIgnored    []string
-		wantNotIgnored []string
-	}{
-		{
-			name: "no ignore",
-		},
-		{
-			name: "ignores without wildcard",
-			ignorePkgs: map[string]bool{
-				"a/b/c":   true,
-				"m/n":     true,
-				"gophers": true,
-			},
-			wantIgnored:    []string{"a/b/c", "m/n", "gophers"},
-			wantNotIgnored: []string{"somerandomstring"},
-		},
-		{
-			name: "ignores with wildcard",
-			ignorePkgs: map[string]bool{
-				"a/b/c*":    true,
-				"m/n*/o":    true,
-				"*x/y/z":    true,
-				"A/B*/C/D*": true,
-			},
-			wantIgnored:    []string{"a/b/c", "a/b/c/d", "a/b/c-d", "m/n*/o", "*x/y/z", "A/B*/C/D", "A/B*/C/D/E"},
-			wantNotIgnored: []string{"m/n/o", "m/n*", "x/y/z", "*x/y/z/a", "*x", "A/B", "A/B*/C"},
-		},
-	}
-
-	for _, c := range cases {
-		t.Run(c.name, func(t *testing.T) {
-			rd := rootdata{
-				ig:    c.ignorePkgs,
-				igpfx: pkgtree.CreateIgnorePrefixTree(c.ignorePkgs),
-			}
-
-			for _, p := range c.wantIgnored {
-				if !rd.isIgnored(p) {
-					t.Fatalf("expected %q to be ignored", p)
-				}
-			}
-
-			for _, p := range c.wantNotIgnored {
-				if rd.isIgnored(p) {
-					t.Fatalf("expected %q to be not ignored", p)
-				}
-			}
-		})
-	}
-}
diff --git a/internal/gps/solve_bimodal_test.go b/internal/gps/solve_bimodal_test.go
index 668ab1dff2..e55e875415 100644
--- a/internal/gps/solve_bimodal_test.go
+++ b/internal/gps/solve_bimodal_test.go
@@ -1345,12 +1345,9 @@ func (f bimodalFixture) rootmanifest() RootManifest {
 	m := simpleRootManifest{
 		c:   pcSliceToMap(f.ds[0].deps),
 		ovr: f.ovr,
-		ig:  make(map[string]bool),
+		ig:  pkgtree.NewIgnoredRuleset(f.ignore),
 		req: make(map[string]bool),
 	}
-	for _, ig := range f.ignore {
-		m.ig[ig] = true
-	}
 	for _, req := range f.require {
 		m.req[req] = true
 	}
diff --git a/internal/gps/solver.go b/internal/gps/solver.go
index 106ab5351a..a325101a9d 100644
--- a/internal/gps/solver.go
+++ b/internal/gps/solver.go
@@ -184,7 +184,7 @@ func (params SolveParameters) toRootdata() (rootdata, error) {
 	}
 
 	rd := rootdata{
-		ig:      params.Manifest.IgnoredPackages(),
+		ir:      params.Manifest.IgnoredPackages(),
 		req:     params.Manifest.RequiredPackages(),
 		ovr:     params.Manifest.Overrides(),
 		rpt:     params.RootPackageTree.Copy(),
@@ -195,10 +195,7 @@ func (params SolveParameters) toRootdata() (rootdata, error) {
 		an:      params.ProjectAnalyzer,
 	}
 
-	// Ensure the required, ignore and overrides maps are at least initialized
-	if rd.ig == nil {
-		rd.ig = make(map[string]bool)
-	}
+	// Ensure the required and overrides maps are at least initialized
 	if rd.req == nil {
 		rd.req = make(map[string]bool)
 	}
@@ -206,13 +203,10 @@ func (params SolveParameters) toRootdata() (rootdata, error) {
 		rd.ovr = make(ProjectConstraints)
 	}
 
-	// Create ignore prefix tree using the provided ignore packages
-	rd.igpfx = pkgtree.CreateIgnorePrefixTree(rd.ig)
-
-	if len(rd.ig) != 0 {
+	if rd.ir.Len() > 0 {
 		var both []string
 		for pkg := range params.Manifest.RequiredPackages() {
-			if rd.isIgnored(pkg) {
+			if rd.ir.IsIgnored(pkg) {
 				both = append(both, pkg)
 			}
 		}
@@ -633,7 +627,7 @@ func (s *solver) getImportsAndConstraintsOf(a atomWithPackages) ([]string, []com
 		return nil, nil, err
 	}
 
-	rm, em := ptree.ToReachMap(true, false, true, s.rd.ig)
+	rm, em := ptree.ToReachMap(true, false, true, s.rd.ir)
 	// Use maps to dedupe the unique internal and external packages.
 	exmap, inmap := make(map[string]struct{}), make(map[string]struct{})
 
@@ -661,14 +655,14 @@ func (s *solver) getImportsAndConstraintsOf(a atomWithPackages) ([]string, []com
 	// explicitly listed in the atom
 	for _, pkg := range a.pl {
 		// Skip ignored packages
-		if s.rd.isIgnored(pkg) {
+		if s.rd.ir.IsIgnored(pkg) {
 			continue
 		}
 
 		ie, exists := rm[pkg]
 		if !exists {
 			// Missing package here *should* only happen if the target pkg was
-			// poisoned. Check the errors map
+			// poisoned; check the errors map.
 			if importErr, eexists := em[pkg]; eexists {
 				return nil, nil, importErr
 			}
diff --git a/internal/gps/solver_inputs_test.go b/internal/gps/solver_inputs_test.go
index 3784c2fdd0..0393597fdc 100644
--- a/internal/gps/solver_inputs_test.go
+++ b/internal/gps/solver_inputs_test.go
@@ -94,7 +94,7 @@ func TestBadSolveOpts(t *testing.T) {
 	}
 
 	params.Manifest = simpleRootManifest{
-		ig:  map[string]bool{"foo": true},
+		ig:  pkgtree.NewIgnoredRuleset([]string{"foo"}),
 		req: map[string]bool{"foo": true},
 	}
 	_, err = Prepare(params, sm)
@@ -105,7 +105,7 @@ func TestBadSolveOpts(t *testing.T) {
 	}
 
 	params.Manifest = simpleRootManifest{
-		ig:  map[string]bool{"foo": true, "bar": true},
+		ig:  pkgtree.NewIgnoredRuleset([]string{"foo", "bar"}),
 		req: map[string]bool{"foo": true, "bar": true},
 	}
 	_, err = Prepare(params, sm)
@@ -116,7 +116,7 @@ func TestBadSolveOpts(t *testing.T) {
 	}
 
 	params.Manifest = simpleRootManifest{
-		ig:  map[string]bool{"foo*": true},
+		ig:  pkgtree.NewIgnoredRuleset([]string{"foo*"}),
 		req: map[string]bool{"foo/bar": true},
 	}
 	_, err = Prepare(params, sm)
diff --git a/internal/gps/source_cache_bolt_encode.go b/internal/gps/source_cache_bolt_encode.go
index c00513afed..006c6ca4de 100644
--- a/internal/gps/source_cache_bolt_encode.go
+++ b/internal/gps/source_cache_bolt_encode.go
@@ -104,7 +104,7 @@ func cachePutManifest(b *bolt.Bucket, m Manifest) error {
 		return nil
 	}
 
-	ignored := rm.IgnoredPackages()
+	ignored := rm.IgnoredPackages().ToSlice()
 	if len(ignored) > 0 {
 		ig, err := b.CreateBucket(cacheKeyIgnored)
 		if err != nil {
@@ -112,13 +112,11 @@ func cachePutManifest(b *bolt.Bucket, m Manifest) error {
 		}
 		key := make(nuts.Key, nuts.KeyLen(uint64(len(ignored)-1)))
 		var i uint64
-		for ip, ok := range ignored {
-			if ok {
-				key.Put(i)
-				i++
-				if err := ig.Put(key, []byte(ip)); err != nil {
-					return err
-				}
+		for _, ip := range ignored {
+			key.Put(i)
+			i++
+			if err := ig.Put(key, []byte(ip)); err != nil {
+				return err
 			}
 		}
 	}
@@ -173,7 +171,6 @@ func cacheGetManifest(b *bolt.Bucket) (RootManifest, error) {
 	m := &simpleRootManifest{
 		c:   make(ProjectConstraints),
 		ovr: make(ProjectConstraints),
-		ig:  make(map[string]bool),
 		req: make(map[string]bool),
 	}
 
@@ -198,10 +195,12 @@ func cacheGetManifest(b *bolt.Bucket) (RootManifest, error) {
 
 	// Ignored
 	if ig := b.Bucket(cacheKeyIgnored); ig != nil {
+		var igslice []string
 		err := ig.ForEach(func(_, v []byte) error {
-			m.ig[string(v)] = true
+			igslice = append(igslice, string(v))
 			return nil
 		})
+		m.ig = pkgtree.NewIgnoredRuleset(igslice)
 		if err != nil {
 			return nil, errors.Wrap(err, "failed to get ignored")
 		}
diff --git a/internal/gps/source_cache_test.go b/internal/gps/source_cache_test.go
index 7331b4396a..e219f4858f 100644
--- a/internal/gps/source_cache_test.go
+++ b/internal/gps/source_cache_test.go
@@ -7,6 +7,7 @@ package gps
 import (
 	"io/ioutil"
 	"log"
+	"reflect"
 	"sort"
 	"testing"
 	"time"
@@ -100,14 +101,11 @@ func (test singleSourceCacheTest) run(t *testing.T) {
 					Constraint: testSemverConstraint(t, "2.0.0"),
 				},
 			},
-			ig: map[string]bool{
-				"a": true,
-				"b": true,
-			},
 			req: map[string]bool{
 				"c": true,
 				"d": true,
 			},
+			ig: pkgtree.NewIgnoredRuleset([]string{"a", "b"}),
 		}
 		var l Lock = &safeLock{
 			h: []byte("test_hash"),
@@ -149,14 +147,11 @@ func (test singleSourceCacheTest) run(t *testing.T) {
 					Constraint: testSemverConstraint(t, "2.0.0"),
 				},
 			},
-			ig: map[string]bool{
-				"c": true,
-				"d": true,
-			},
 			req: map[string]bool{
 				"a": true,
 				"b": true,
 			},
+			ig: pkgtree.NewIgnoredRuleset([]string{"c", "d"}),
 		}
 		l = &safeLock{
 			h: []byte("different_test_hash"),
@@ -416,7 +411,7 @@ func compareManifests(t *testing.T, want, got Manifest) {
 
 	{
 		want, got := wantRM.IgnoredPackages(), gotRM.IgnoredPackages()
-		if !mapStringBoolEqual(want, got) {
+		if !reflect.DeepEqual(want.ToSlice(), got.ToSlice()) {
 			t.Errorf("unexpected ignored packages:\n\t(GOT): %#v\n\t(WNT): %#v", got, want)
 		}
 	}
diff --git a/internal/gps/trace.go b/internal/gps/trace.go
index 2f75b6ee47..05976573b6 100644
--- a/internal/gps/trace.go
+++ b/internal/gps/trace.go
@@ -117,7 +117,7 @@ func (s *solver) traceSelectRoot(ptree pkgtree.PackageTree, cdeps []completeDep)
 
 	// This duplicates work a bit, but we're in trace mode and it's only once,
 	// so who cares
-	rm, _ := ptree.ToReachMap(true, true, false, s.rd.ig)
+	rm, _ := ptree.ToReachMap(true, true, false, s.rd.ir)
 
 	s.tl.Printf("Root project is %q", s.rd.rpt.ImportRoot)
 
diff --git a/internal/test/integration/testcase.go b/internal/test/integration/testcase.go
index 6e2934eb71..bd772da7d8 100644
--- a/internal/test/integration/testcase.go
+++ b/internal/test/integration/testcase.go
@@ -83,21 +83,38 @@ func (tc *TestCase) CompareFile(goldenPath, working string) {
 
 	gotExists, got, err := getFile(working)
 	if err != nil {
-		tc.t.Fatalf("Error reading project file %s: %s", goldenPath, err)
+		tc.t.Fatalf("Error reading project file %q: %s", goldenPath, err)
 	}
 	wantExists, want, err := getFile(golden)
 	if err != nil {
-		tc.t.Fatalf("Error reading testcase file %s: %s", goldenPath, err)
+		tc.t.Fatalf("Error reading testcase file %q: %s", goldenPath, err)
 	}
 
 	if wantExists && gotExists {
 		if want != got {
-			tc.t.Errorf("expected %s, got %s", want, got)
+			tc.t.Errorf("%s was not as expected\n(WNT):\n%s\n(GOT):\n%s", filepath.Base(goldenPath), want, got)
 		}
 	} else if !wantExists && gotExists {
-		tc.t.Errorf("%s created where none was expected", goldenPath)
+		tc.t.Errorf("%q created where none was expected", goldenPath)
 	} else if wantExists && !gotExists {
-		tc.t.Errorf("%s not created where one was expected", goldenPath)
+		tc.t.Errorf("%q not created where one was expected", goldenPath)
+	}
+}
+
+// UpdateOutput updates the golden file for stdout with the working result.
+func (tc *TestCase) UpdateOutput(stdout string) {
+	stdoutPath := filepath.Join(tc.rootPath, "stdout.txt")
+	_, err := os.Stat(stdoutPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			// Don't update the stdout.txt file if it doesn't exist.
+			return
+		}
+		panic(err)
+	}
+
+	if err := tc.WriteFile(stdoutPath, stdout); err != nil {
+		tc.t.Fatal(err)
 	}
 }
 
@@ -116,7 +133,7 @@ func (tc *TestCase) CompareOutput(stdout string) {
 	stdout = normalizeLines(stdout)
 
 	if expStr != stdout {
-		tc.t.Errorf("(WNT):\n%s\n(GOT):\n%s\n", expStr, stdout)
+		tc.t.Errorf("stdout was not as expected\n(WNT):\n%s\n(GOT):\n%s\n", expStr, stdout)
 	}
 }
 
diff --git a/manifest.go b/manifest.go
index 2140992210..87ea79292a 100644
--- a/manifest.go
+++ b/manifest.go
@@ -14,6 +14,7 @@ import (
 	"sync"
 
 	"github.com/golang/dep/internal/gps"
+	"github.com/golang/dep/internal/gps/pkgtree"
 	"github.com/pelletier/go-toml"
 	"github.com/pkg/errors"
 )
@@ -53,7 +54,7 @@ type rawProject struct {
 	Source   string `toml:"source,omitempty"`
 }
 
-// NewManifest instantites a new manifest.
+// NewManifest instantiates a new manifest.
 func NewManifest() *Manifest {
 	return &Manifest{
 		Constraints: make(gps.ProjectConstraints),
@@ -376,17 +377,8 @@ func (m *Manifest) Overrides() gps.ProjectConstraints {
 }
 
 // IgnoredPackages returns a set of import paths to ignore.
-func (m *Manifest) IgnoredPackages() map[string]bool {
-	if len(m.Ignored) == 0 {
-		return nil
-	}
-
-	mp := make(map[string]bool, len(m.Ignored))
-	for _, i := range m.Ignored {
-		mp[i] = true
-	}
-
-	return mp
+func (m *Manifest) IgnoredPackages() *pkgtree.IgnoredRuleset {
+	return pkgtree.NewIgnoredRuleset(m.Ignored)
 }
 
 // HasConstraintsOn checks if the manifest contains either constraints or