diff --git a/python/mozbuild/mozbuild/code-analysis/mach_commands.py b/python/mozbuild/mozbuild/code-analysis/mach_commands.py
index 57fe5b785e74..a372d0cf5a3f 100644
--- a/python/mozbuild/mozbuild/code-analysis/mach_commands.py
+++ b/python/mozbuild/mozbuild/code-analysis/mach_commands.py
@@ -93,7 +93,7 @@ class StaticAnalysisMonitor(object):
         for item in self._clang_tidy_config:
             if item['name'] == '-*':
                 continue
-            item['name'].replace('*', '.*')
+            item['name'] = item['name'].replace('*', '.*')
 
         from mozbuild.compilation.warnings import (
             WarningsCollector,