diff --git a/google/oauth2/service_account.py b/google/oauth2/service_account.py
index 61fca9d1b..4612d73d4 100644
--- a/google/oauth2/service_account.py
+++ b/google/oauth2/service_account.py
@@ -507,7 +507,7 @@ def signer_email(self):
     @_helpers.copy_docstring(credentials.Credentials)
     def _get_cred_info(self):
         if self._cred_file_path and self.service_account_email:
-            return f"This API call is authenticated as {self.service_account_email} from {self._source} via the GOOGLE_APPLICATION_CREDENTIALS environment variable."
+            return f"This API call is authenticated as {self.service_account_email} from {self._cred_file_path} via the GOOGLE_APPLICATION_CREDENTIALS environment variable."
         if self._cred_file_path:
             return f"This API call is authenticated from {self._cred_file_path} via the GOOGLE_APPLICATION_CREDENTIALS environment variable."
         return None