diff --git a/google/genai/_api_client.py b/google/genai/_api_client.py
index 1812df911..e240545f5 100644
--- a/google/genai/_api_client.py
+++ b/google/genai/_api_client.py
@@ -125,14 +125,14 @@ def append_library_version_headers(headers: dict[str, str]) -> None:
   version_header_value = f'{library_label} {language_label}'
   if (
       'user-agent' in headers
-      and version_header_value not in headers['user-agent']
+      and library_label not in headers['user-agent']
   ):
     headers['user-agent'] = f'{version_header_value} ' + headers['user-agent']
   elif 'user-agent' not in headers:
     headers['user-agent'] = version_header_value
   if (
       'x-goog-api-client' in headers
-      and version_header_value not in headers['x-goog-api-client']
+      and library_label not in headers['x-goog-api-client']
   ):
     headers['x-goog-api-client'] = (
         f'{version_header_value} ' + headers['x-goog-api-client']