diff --git a/obj/obj_test.go b/obj/obj_test.go
index 2a90bad..924d94b 100644
--- a/obj/obj_test.go
+++ b/obj/obj_test.go
@@ -2,8 +2,9 @@ package obj
 
 import (
 	"fmt"
-	"regexp"
 	"testing"
+
+	tu "github.com/bayashi/witness/testutil"
 )
 
 type Example struct {
@@ -69,9 +70,8 @@ func TestBooleanPointer(t *testing.T) {
 	f := false
 	o := NewObject(&f)
 
-	expectRe := regexp.MustCompile(`\(\*bool\)\([0-9a-fx]+\)\(false\)`)
-	if expectRe.FindStringSubmatch(o.AsString()) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", expectRe.String(), o.AsString())
+	if ok, msg := tu.Match(`\(\*bool\)\([0-9a-fx]+\)\(false\)`, o.AsString()); !ok {
+		t.Error(msg)
 	}
 }
 
@@ -79,9 +79,8 @@ func TestError(t *testing.T) {
 	e := fmt.Errorf("foo error")
 	o := NewObject(e)
 
-	expectRe := regexp.MustCompile(`\(\*errors\.errorString\)\([0-9a-fx]+\)\(foo error\)`)
-	if expectRe.FindStringSubmatch(o.AsString()) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", expectRe.String(), o.AsString())
+	if ok, msg := tu.Match(`\(\*errors\.errorString\)\([0-9a-fx]+\)\(foo error\)`, o.AsString()); !ok {
+		t.Error(msg)
 	}
 }
 
@@ -89,9 +88,8 @@ func TestPointerValueInt(t *testing.T) {
 	i := 123
 	o := NewObject(&i)
 
-	expectRe := regexp.MustCompile(`\(\*int\)\([0-9a-fx]+\)\(123\)`)
-	if expectRe.FindStringSubmatch(o.AsString()) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", expectRe.String(), o.AsString())
+	if ok, msg := tu.Match(`\(\*int\)\([0-9a-fx]+\)\(123\)`, o.AsString()); !ok {
+		t.Error(msg)
 	}
 }
 
@@ -99,9 +97,8 @@ func TestPointerValueFloat(t *testing.T) {
 	var i float64 = 0.123
 	o := NewObject(&i)
 
-	expectRe := regexp.MustCompile(`\(*float64\)\([0-9a-fx]+\)\(0\.123\)`)
-	if expectRe.FindStringSubmatch(o.AsString()) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", expectRe.String(), o.AsString())
+	if ok, msg := tu.Match(`\(*float64\)\([0-9a-fx]+\)\(0\.123\)`, o.AsString()); !ok {
+		t.Error(msg)
 	}
 }
 
@@ -109,9 +106,8 @@ func TestStructValue(t *testing.T) {
 	i := struct{ ID int }{ ID: 123 }
 	o := NewObject(i)
 
-	expectRe := regexp.MustCompile(`struct { ID int }{ID:123}`)
-	if expectRe.FindStringSubmatch(o.AsString()) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", expectRe.String(), o.AsString())
+	if ok, msg := tu.Match(`struct { ID int }{ID:123}`, o.AsString()); !ok {
+		t.Error(msg)
 	}
 }
 
@@ -119,9 +115,8 @@ func TestStructPointerValue(t *testing.T) {
 	i := struct{ ID int }{ ID: 123 }
 	o := NewObject(&i)
 
-	expectRe := regexp.MustCompile(`[0-9a-fx]+, &struct { ID int }{ID:123}`)
-	if expectRe.FindStringSubmatch(o.AsString()) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", expectRe.String(), o.AsString())
+	if ok, msg := tu.Match(`[0-9a-fx]+, &struct { ID int }{ID:123}`, o.AsString()); !ok {
+		t.Error(msg)
 	}
 }
 
diff --git a/testutil/regexp.go b/testutil/regexp.go
new file mode 100644
index 0000000..1cae29b
--- /dev/null
+++ b/testutil/regexp.go
@@ -0,0 +1,15 @@
+package testutil
+
+import (
+	"fmt"
+	"regexp"
+)
+
+func Match(re string, target string) (bool, string) {
+	reg := regexp.MustCompile(re)
+	if !reg.MatchString(target) {
+		return false, fmt.Sprintf("Not matched the regexp `%s` for %q", reg.String(), target)
+	}
+
+	return true, ""
+}
diff --git a/trace/trace_test.go b/trace/trace_test.go
index 80f6bfe..a0ec21d 100644
--- a/trace/trace_test.go
+++ b/trace/trace_test.go
@@ -1,8 +1,9 @@
 package trace
 
 import (
-	"regexp"
 	"testing"
+
+	tu "github.com/bayashi/witness/testutil"
 )
 
 func TestInfo(t *testing.T) {
@@ -10,9 +11,9 @@ func TestInfo(t *testing.T) {
 	if len(trace) != 1 {
 		t.Error("trace length should be 1.")
 	}
-	var traceRegexp = regexp.MustCompile(`/witness/trace/trace_test\.go:\d+$`)
-	if !traceRegexp.MatchString(trace[0]) {
-		t.Errorf("trace was not match Regexp:`%s`, Got:`%s`", traceRegexp.String(), trace[0])
+
+	if ok, msg := tu.Match(`/witness/trace/trace_test\.go:\d+$`, trace[0]); !ok {
+		t.Error(msg)
 	}
 }
 
diff --git a/witness_test.go b/witness_test.go
index c90221f..c36febd 100644
--- a/witness_test.go
+++ b/witness_test.go
@@ -2,11 +2,11 @@ package witness
 
 import (
 	"fmt"
-	"regexp"
 	"strings"
 	"testing"
 
 	"github.com/bayashi/witness/report"
+	tu "github.com/bayashi/witness/testutil"
 )
 
 // Global variables to check result
@@ -35,19 +35,16 @@ func TestNil(t *testing.T) {
 	// Expected:       <nil>
 	// Actually got:   <nil>
 
-	gotTypeRe := regexp.MustCompile(`Type:\s*\tExpect:<nil>, Got:<nil>`)
-	if gotTypeRe.FindStringSubmatch(res) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", gotTypeRe.String(), res)
+	if ok, msg := tu.Match(`Type:\s*\tExpect:<nil>, Got:<nil>`, res); !ok {
+		t.Error(msg)
 	}
 
-	expectRe := regexp.MustCompile(`Expected:\s*\t<nil>`)
-	if expectRe.FindStringSubmatch(res) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", expectRe.String(), res)
+	if ok, msg := tu.Match(`Expected:\s*\t<nil>`, res); !ok {
+		t.Error(msg)
 	}
 
-	gotRe := regexp.MustCompile(`Actually got:\s*\t<nil>`)
-	if gotRe.FindStringSubmatch(res) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", gotRe.String(), res)
+	if ok, msg := tu.Match(`Actually got:\s*\t<nil>`, res); !ok {
+		t.Error(msg)
 	}
 }
 
@@ -61,14 +58,12 @@ func TestError(t *testing.T) {
     // Type:           Got:*errors.errorString
     // Actually got:   error example 123
 
-	gotTypeRe := regexp.MustCompile(`Type:\s*\tGot:\*errors\.errorString`)
-	if gotTypeRe.FindStringSubmatch(res) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", gotTypeRe.String(), res)
+	if ok, msg := tu.Match(`Type:\s*\tGot:\*errors\.errorString`, res); !ok {
+		t.Error(msg)
 	}
 
-	gotRe := regexp.MustCompile(`Actually got:\s*\t\(\*errors\.errorString\)\([0-9a-fx]+\)\(error example 123\)`)
-	if gotRe.FindStringSubmatch(res) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", gotRe.String(), res)
+	if ok, msg := tu.Match(`Actually got:\s*\t\(\*errors\.errorString\)\([0-9a-fx]+\)\(error example 123\)`, res); !ok {
+		t.Error(msg)
 	}
 }
 
@@ -106,9 +101,8 @@ func TestFailGot(t *testing.T) {
 		t.Errorf("Expected to be contained type, but not: %q", res)
 	}
 
-	gotRe := regexp.MustCompile(fmt.Sprintf("Actually got:\\s*\\t%q", got))
-	if gotRe.FindStringSubmatch(res) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", gotRe.String(), res)
+	if ok, msg := tu.Match(fmt.Sprintf("Actually got:\\s*\\t%q", got), res); !ok {
+		t.Error(msg)
 	}
 }
 
@@ -144,14 +138,12 @@ func TestFailGotExpect(t *testing.T) {
 		t.Errorf("Expected to be contained types, but not: %q", res)
 	}
 
-	gotRe := regexp.MustCompile(fmt.Sprintf("Actually got:\\s*\\t%q", got))
-	if gotRe.FindStringSubmatch(res) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", gotRe.String(), res)
+	if ok, msg := tu.Match(fmt.Sprintf("Actually got:\\s*\\t%q", got), res); !ok {
+		t.Error(msg)
 	}
 
-	expectRe := regexp.MustCompile(fmt.Sprintf("Expected:\\s*\\t%q", expect))
-	if expectRe.FindStringSubmatch(res) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", expectRe.String(), res)
+	if ok, msg := tu.Match(fmt.Sprintf("Expected:\\s*\\t%q", expect), res); !ok {
+		t.Error(msg)
 	}
 }
 
@@ -181,9 +173,8 @@ func TestFailWithDiff(t *testing.T) {
 		t.Errorf("Expected to be contained the string `Diff details:`, but not: %q", res)
 	}
 
-	diffRe := regexp.MustCompile("\\s*a\n\\s*-d\n\\s*\\+b\n\\s*c")
-	if diffRe.FindStringSubmatch(res) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", diffRe.String(), res)
+	if ok, msg := tu.Match("\\s*a\n\\s*-d\n\\s*\\+b\n\\s*c", res); !ok {
+		t.Error(msg)
 	}
 }
 
@@ -212,14 +203,12 @@ func TestFailWithRawData(t *testing.T) {
 	//                 c
 	//                 ---
 
-	rawExpectRe := regexp.MustCompile("Raw Expect:\\s*\t---\n\\s*a\n\\s*d")
-	if rawExpectRe.FindStringSubmatch(res) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", rawExpectRe.String(), res)
+	if ok, msg := tu.Match("Raw Expect:\\s*\t---\n\\s*a\n\\s*d", res); !ok {
+		t.Error(msg)
 	}
 
-	rawGotRe := regexp.MustCompile("Raw Got:\\s*\t---\n\\s*a\n\\s*b")
-	if rawGotRe.FindStringSubmatch(res) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", rawGotRe.String(), res)
+	if ok, msg := tu.Match("Raw Got:\\s*\t---\n\\s*a\n\\s*b", res); !ok {
+		t.Error(msg)
 	}
 }
 
@@ -237,8 +226,7 @@ func TestFailWithAdditionalMessage(t *testing.T) {
 	// Actually got:   "a\nb\nc"
 	// Example Label:  Some info
 
-	infoRe := regexp.MustCompile("Example Label:\\s*\tSome info\n")
-	if infoRe.FindStringSubmatch(res) == nil {
-		t.Errorf("Not matched the regexp `%s` for %q", infoRe.String(), res)
+	if ok, msg := tu.Match("Example Label:\\s*\tSome info\n", res); !ok {
+		t.Error(msg)
 	}
 }