diff --git a/dom/canvas/test/webgl-conf/generate-wrappers-and-manifest.py b/dom/canvas/test/webgl-conf/generate-wrappers-and-manifest.py
index e2ea58aec1fd..7ab6eadf061e 100755
--- a/dom/canvas/test/webgl-conf/generate-wrappers-and-manifest.py
+++ b/dom/canvas/test/webgl-conf/generate-wrappers-and-manifest.py
@@ -539,7 +539,7 @@ def GetFilePathListForDir(baseDir):
 
 if __name__ == '__main__':
     file_dir = Path(__file__).parent
-    os.chdir(file_dir)
+    os.chdir(str(file_dir))
 
     testEntryList = GetTestList()
     wrapperPathStrList = WriteWrappers(testEntryList)