diff --git a/git-codereview/gofmt.go b/git-codereview/gofmt.go
index 12ea801..f47c43d 100644
--- a/git-codereview/gofmt.go
+++ b/git-codereview/gofmt.go
@@ -348,6 +348,9 @@
 	if strings.HasPrefix(file, "vendor/") || strings.Contains(file, "/vendor/") {
 		return false
 	}
+	if strings.HasPrefix(file, "testdata/") || strings.Contains(file, "/testdata/") {
+		return false
+	}
 	if !strings.HasPrefix(file, "test/") {
 		return true
 	}