diff --git a/tests/misra/test_mutation.py b/tests/misra/test_mutation.py
index 0adfba67ef0..b24a0791599 100755
--- a/tests/misra/test_mutation.py
+++ b/tests/misra/test_mutation.py
@@ -65,6 +65,11 @@
 files = [f for f in all_files if f.endswith(('.c', '.h')) and not f.startswith(IGNORED_PATHS)]
 assert len(files) > 70, all(d in files for d in ('board/main.c', 'board/stm32f4/llbxcan.h', 'board/stm32h7/llfdcan.h', 'board/safety/safety_toyota.h'))
 
+# Remove cppcheck files from previous runs to speed tree copying
+for f in glob.glob(f"{ROOT}/**/*", recursive=True):
+    if f.endswith(('.dump', '.ctu-info')):
+        os.remove(f)
+
 for p in patterns:
   mutations.append((random.choice(files), p, True))