diff --git a/tests/test_modutils.py b/tests/test_modutils.py
index f2f2c960c0..26618c7ec3 100644
--- a/tests/test_modutils.py
+++ b/tests/test_modutils.py
@@ -270,7 +270,7 @@ def test_std_lib(self) -> None:
 
     def test_std_lib_found_before_same_named_package_on_path(self) -> None:
         realpath = str(resources.RESOURCE_PATH)
-        realpath_slashes = realpath.replace('\\', '\\\\')
+        realpath_slashes = realpath.replace("\\", "\\\\")
         if WIN32:
             raise AssertionError(realpath + realpath_slashes)
         sys.path.insert(0, realpath)