diff --git a/check/testfiles/testdata/a.go b/check/testfiles/testdata/a.go
new file mode 100644
index 0000000..69d29d3
--- /dev/null
+++ b/check/testfiles/testdata/a.go
@@ -0,0 +1 @@
+package testdata
diff --git a/check/utils.go b/check/utils.go
index 4c3cd60..dc9e20d 100644
--- a/check/utils.go
+++ b/check/utils.go
@@ -16,7 +16,7 @@ import (
 )
 
 var (
-	skipDirs       = []string{"Godeps", "vendor", "third_party"}
+	skipDirs       = []string{"Godeps", "vendor", "third_party", "testdata"}
 	skipSuffixes   = []string{".pb.go", ".pb.gw.go", ".generated.go", "bindata.go", "_string.go"}
 	skipFirstLines = []string{"code generated", "generated", "autogenerated", "@generated", "code autogenerated", "auto-generated"}
 )