diff --git a/src/Mod/Path/PathScripts/PathToolBitLibraryGui.py b/src/Mod/Path/PathScripts/PathToolBitLibraryGui.py
index 621ad0e996..0abc2a6ae4 100644
--- a/src/Mod/Path/PathScripts/PathToolBitLibraryGui.py
+++ b/src/Mod/Path/PathScripts/PathToolBitLibraryGui.py
@@ -87,7 +87,7 @@ def checkWorkingDir():
 
     subdirlist = ['Bit', 'Library', 'Shape']
     mode = 0o777
-    for dir in subdirlist:
+    for dir in subdirlist.copy():
         subdir = "{}{}{}".format(workingdir, os.path.sep, dir)
         if os.path.exists(subdir):
             subdirlist.remove(dir)