diff --git a/docs/Pipfile.lock b/docs/Pipfile.lock
index f6e69ccd45..35073c37a4 100644
--- a/docs/Pipfile.lock
+++ b/docs/Pipfile.lock
@@ -154,6 +154,7 @@
                 "sha256:028ff3aadf0609c1fd278d8ea3089299412a7a8b9bd005dd08b9f8285bcb5cfc",
                 "sha256:82fee1fc78add43492d3a1898bfa6d8a904cc97d8427f683ed8e798d07761aa0"
             ],
+            "index": "pypi",
             "markers": "python_version >= '3.5'",
             "version": "==3.7"
         },