diff --git a/tests/gateway/test_run_tool_media_re.py b/tests/gateway/test_run_tool_media_re.py
index 67b496d1ddc..8f6da226876 100644
--- a/tests/gateway/test_run_tool_media_re.py
+++ b/tests/gateway/test_run_tool_media_re.py
@@ -1,4 +1,4 @@
-"""Tests for _TOOL_MEDIA_RE regex patterns in gateway/run.py.
+r"""Tests for _TOOL_MEDIA_RE regex patterns in gateway/run.py.
 
 Issue #34632: The _TOOL_MEDIA_RE patterns in GatewayRunner used (?:/|~\/) to
 anchor paths, which only matched Unix-style absolute and home-relative paths.