diff --git a/python/private/pypi/parse_simpleapi_html.bzl b/python/private/pypi/parse_simpleapi_html.bzl
index b4e7dd8330..e549e76181 100644
--- a/python/private/pypi/parse_simpleapi_html.bzl
+++ b/python/private/pypi/parse_simpleapi_html.bzl
@@ -138,4 +138,4 @@ def _absolute_url(index_url, candidate):
         return "{}/{}".format(index_url, last.strip("/"))
 
     # relative path without up-references
-    return "{}/{}".format(index_url, candidate)
+    return "{}/{}".format(index_url.rstrip("/"), candidate)