diff --git a/scripts/tracetool.py b/scripts/tracetool.py
index 629b2593c846f9559e845998f8f434d9dd383f92..fe9c9e904b0304195c9d7a1c4d734f1e97cb3ded 100755
--- a/scripts/tracetool.py
+++ b/scripts/tracetool.py
@@ -70,7 +70,7 @@ def make_group_name(filename):
 
     if dirname == "":
         return "common"
-    return re.sub(r"/|-", "_", dirname)
+    return re.sub(r"[^A-Za-z0-9]", "_", dirname)
 
 def main(args):
     global _SCRIPT