diff --git a/.golangci.yml b/.golangci.yml
index afc01a3ed..624a84829 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -1,8 +1,3 @@
-run:
-  skip-file:
-    - ".+\\.pb\\.go"
-    - ".+\\.pb\\.gw\\.go"
-
 linters-settings:
   govet:
     check-shadowing: false
@@ -17,6 +12,12 @@ linters-settings:
     min-occurrences: 3
   misspell:
     locale: US
+  depguard:
+    list-type: blacklist
+    packages:
+      - golang.org/x/net/context
+      - github.com/gogo/protobuf/proto
+      - github.com/google/martian/log
 
 linters:
   enable-all: true
@@ -30,4 +31,4 @@ linters:
 
 issues:
   exclude:
-    - .((os\.)?std(out|err)\..*|.*Close|.*Flush|.*Write|.*Serve|os\.Remove(All)?|.*printf?|os\.(Un)?Setenv).
+    - .(.*Write|.*Serve).
diff --git a/.travis.yml b/.travis.yml
index 9dddcb801..9b2bdf5d8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -34,7 +34,7 @@ before_install:
 
 install:
   - gcloud -q components install kubectl
-  - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(go env GOPATH)/bin v1.13.1
+  - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(go env GOPATH)/bin v1.13.2
   - go get -t ./...
 
 script:
diff --git a/cmd/gen-test-vectors/main.go b/cmd/gen-test-vectors/main.go
index 06be985da..be39c1a6b 100644
--- a/cmd/gen-test-vectors/main.go
+++ b/cmd/gen-test-vectors/main.go
@@ -31,7 +31,6 @@ import (
 	"github.com/google/keytransparency/core/testutil"
 	"github.com/google/keytransparency/impl/authentication"
 	"github.com/google/keytransparency/impl/integration"
-	"github.com/google/martian/log"
 	"github.com/google/tink/go/tink"
 	"github.com/google/trillian/types"
 
@@ -89,7 +88,7 @@ func GenerateTestVectors(ctx context.Context, env *integration.Env) error {
 				MaxBatch:    100,
 			}
 			if _, err := env.Sequencer.RunBatch(ctx, req); err != nil {
-				log.Errorf("RunBatch(): %v", err)
+				glog.Errorf("RunBatch(): %v", err)
 			}
 		})
 	}()
diff --git a/cmd/keytransparency-client/cmd/post.go b/cmd/keytransparency-client/cmd/post.go
index 3832d8e7e..0314a9dcf 100644
--- a/cmd/keytransparency-client/cmd/post.go
+++ b/cmd/keytransparency-client/cmd/post.go
@@ -75,9 +75,7 @@ User email MUST match the OAuth account used to authorize the update.
 			return fmt.Errorf("hex.Decode(%v): %v", data, err)
 		}
 		userID := args[0]
-		timeout := viper.GetDuration("timeout")
-		ctx, cancel := context.WithTimeout(context.Background(), timeout)
-		defer cancel()
+		ctx := context.Background()
 
 		// Create client.
 		userCreds, err := userCreds(ctx)
@@ -107,7 +105,10 @@ User email MUST match the OAuth account used to authorize the update.
 			PublicKeyData:  profileData,
 			AuthorizedKeys: authorizedKeys.Keyset(),
 		}
-		if _, err := c.Update(ctx, u, []tink.Signer{signer},
+		timeout := viper.GetDuration("timeout")
+		cctx, cancel := context.WithTimeout(ctx, timeout)
+		defer cancel()
+		if _, err := c.Update(cctx, u, []tink.Signer{signer},
 			grpc.PerRPCCredentials(userCreds)); err != nil {
 			return fmt.Errorf("update failed: %v", err)
 		}
diff --git a/core/client/multi/writer.go b/core/client/multi/writer.go
index b610f5670..37b9e3497 100644
--- a/core/client/multi/writer.go
+++ b/core/client/multi/writer.go
@@ -48,7 +48,7 @@ func (m *writer) Write(p []byte) (n int, err error) {
 	for _, w := range m.writers {
 		n, err = w.Write(p)
 		if err != nil {
-			multiError = multiError + fmt.Sprintf("%v bytes written to %v: %v", n, w, err)
+			multiError += fmt.Sprintf("%v bytes written to %v: %v", n, w, err)
 		}
 		minBytesWritten = min(n, minBytesWritten)
 	}
diff --git a/core/crypto/tinkio/pem.go b/core/crypto/tinkio/pem.go
index 7b0741701..8945651eb 100644
--- a/core/crypto/tinkio/pem.go
+++ b/core/crypto/tinkio/pem.go
@@ -20,7 +20,7 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/gogo/protobuf/proto"
+	"github.com/golang/protobuf/proto"
 	"github.com/google/tink/go/signature"
 	"github.com/google/tink/go/testutil"
 	"github.com/google/tink/go/tink"
diff --git a/core/crypto/tinkio/protofile.go b/core/crypto/tinkio/protofile.go
index a2b3364fd..6306f4de5 100644
--- a/core/crypto/tinkio/protofile.go
+++ b/core/crypto/tinkio/protofile.go
@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"io/ioutil"
 
-	"github.com/gogo/protobuf/proto"
+	"github.com/golang/protobuf/proto"
 
 	tinkpb "github.com/google/tink/proto/tink_go_proto"
 )