diff --git a/google/internal/externalaccount/basecredentials.go b/google/internal/externalaccount/basecredentials.go
index dba13df..fdde4ac 100644
--- a/google/internal/externalaccount/basecredentials.go
+++ b/google/internal/externalaccount/basecredentials.go
@@ -255,7 +255,7 @@ func (ts tokenSource) Token() (*oauth2.Token, error) {
 			"userProject": conf.WorkforcePoolUserProject,
 		}
 	}
-	stsResp, err := sts_exchange.ExchangeToken(ts.ctx, conf.TokenURL, &stsRequest, clientAuth, nil, options)
+	stsResp, err := sts_exchange.ExchangeToken(ts.ctx, conf.TokenURL, &stsRequest, clientAuth, header, options)
 	if err != nil {
 		return nil, err
 	}
diff --git a/google/internal/externalaccountauthorizeduser/externalaccountauthorizeduser_test.go b/google/internal/externalaccountauthorizeduser/externalaccountauthorizeduser_test.go
index 38ce434..2d7b854 100644
--- a/google/internal/externalaccountauthorizeduser/externalaccountauthorizeduser_test.go
+++ b/google/internal/externalaccountauthorizeduser/externalaccountauthorizeduser_test.go
@@ -105,7 +105,7 @@ func TestExernalAccountAuthorizedUser_JustToken(t *testing.T) {
 	}
 }
 
-func TestExernalAccountAuthorizedUser_TokenRefreshWithRefreshTokenInResponds(t *testing.T) {
+func TestExernalAccountAuthorizedUser_TokenRefreshWithRefreshTokenInRespondse(t *testing.T) {
 	server := &testRefreshTokenServer{
 		URL:           "/",
 		Authorization: "Basic Q0xJRU5UX0lEOkNMSUVOVF9TRUNSRVQ=",
@@ -147,7 +147,7 @@ func TestExernalAccountAuthorizedUser_TokenRefreshWithRefreshTokenInResponds(t *
 	}
 }
 
-func TestExernalAccountAuthorizedUser_minimumFieldsRequiredForRefresh(t *testing.T) {
+func TestExernalAccountAuthorizedUser_MinimumFieldsRequiredForRefresh(t *testing.T) {
 	server := &testRefreshTokenServer{
 		URL:           "/",
 		Authorization: "Basic Q0xJRU5UX0lEOkNMSUVOVF9TRUNSRVQ=",