diff --git a/google/default.go b/google/default.go
index 7ed02cd..a144d78 100644
--- a/google/default.go
+++ b/google/default.go
@@ -137,7 +137,7 @@
 	// use those credentials. App Engine standard second generation runtimes (>= Go 1.11)
 	// and App Engine flexible use ComputeTokenSource and the metadata server.
 	if appengineTokenFunc != nil {
-		return &DefaultCredentials{
+		return &Credentials{
 			ProjectID:   appengineAppIDFunc(ctx),
 			TokenSource: AppEngineTokenSource(ctx, params.Scopes...),
 		}, nil
@@ -147,7 +147,7 @@
 	// or App Engine flexible, use the metadata server.
 	if metadata.OnGCE() {
 		id, _ := metadata.ProjectID()
-		return &DefaultCredentials{
+		return &Credentials{
 			ProjectID:   id,
 			TokenSource: ComputeTokenSource("", params.Scopes...),
 		}, nil
@@ -194,7 +194,7 @@
 		return nil, err
 	}
 	ts = newErrWrappingTokenSource(ts)
-	return &DefaultCredentials{
+	return &Credentials{
 		ProjectID:   f.ProjectID,
 		TokenSource: ts,
 		JSON:        jsonData,
@@ -216,7 +216,7 @@
 	return filepath.Join(guessUnixHomeDir(), ".config", "gcloud", f)
 }
 
-func readCredentialsFile(ctx context.Context, filename string, params CredentialsParams) (*DefaultCredentials, error) {
+func readCredentialsFile(ctx context.Context, filename string, params CredentialsParams) (*Credentials, error) {
 	b, err := ioutil.ReadFile(filename)
 	if err != nil {
 		return nil, err