diff --git a/xmodule/modulestore/store_utilities.py b/xmodule/modulestore/store_utilities.py
index ced5c9728e..e9710fbc92 100644
--- a/xmodule/modulestore/store_utilities.py
+++ b/xmodule/modulestore/store_utilities.py
@@ -17,11 +17,11 @@ def _prefix_only_url_replace_regex(pattern):
     Match urls in quotes pulling out the fields from pattern
     """
     return re.compile("""
-        (?x)                      # flags=re.VERBOSE
         (?P<quote>\\\\?['"])      # the opening quotes
         {}
         (?P=quote)                # the first matching closing quote
-        """.format(pattern))
+        """.format(pattern),
+        flags=re.VERBOSE)
 
 
 def rewrite_nonportable_content_links(source_course_id, dest_course_id, text):