diff --git a/samples/python/_coverage.py b/samples/python/_coverage.py
index 62dd7aa5d8..634c6b8795 100755
--- a/samples/python/_coverage.py
+++ b/samples/python/_coverage.py
@@ -18,7 +18,7 @@ if __name__ == '__main__':
     for fn in glob('*.py'):
         print(' --- ', fn)
         code = open(fn).read()
-        found |= set(re.findall('cv2?\.\w+', code))
+        found |= set(re.findall(r'cv2?\.\w+', code))
 
     cv2_used = found & cv2_callable
     cv2_unused = cv2_callable - cv2_used