diff --git a/fanficdownloader/adapters/adapter_archiveofourownorg.py b/fanficdownloader/adapters/adapter_archiveofourownorg.py
index eb6eafa4..1abaa754 100644
--- a/fanficdownloader/adapters/adapter_archiveofourownorg.py
+++ b/fanficdownloader/adapters/adapter_archiveofourownorg.py
@@ -84,7 +84,7 @@ class ArchiveOfOurOwnOrgAdapter(BaseSiteAdapter):
     def getSiteURLPattern(self):
         # http://archiveofourown.org/collections/Smallville_Slash_Archive/works/159770
         # Discard leading zeros from story ID numbers--AO3 doesn't use them in it's own chapter URLs.
-        return re.escape("http://")+re.escape(self.getSiteDomain())+r"(/collections/[^/]+)?/works/0*(?P<id>\d+)"
+        return r"https?://"+re.escape(self.getSiteDomain())+r"(/collections/[^/]+)?/works/0*(?P<id>\d+)"
         
     ## Login
     def needToLoginCheck(self, data):