diff --git a/pipenv/patched/pip/_internal/models/search_scope.py b/pipenv/patched/pip/_internal/models/search_scope.py
index 548f32af..76c44656 100644
--- a/pipenv/patched/pip/_internal/models/search_scope.py
+++ b/pipenv/patched/pip/_internal/models/search_scope.py
@@ -136,4 +136,6 @@ class SearchScope:
         index_urls = self.index_urls
         if project_name in self.index_lookup:
             index_urls = [self.index_lookup[project_name]]
+        else:
+            index_urls = [self.index_urls[0]]
         return [mkurl_pypi_url(url) for url in index_urls]
diff --git a/tasks/vendoring/patches/patched/pip_index_safety.patch b/tasks/vendoring/patches/patched/pip_index_safety.patch
index 3cb7100a..ad38b893 100644
--- a/tasks/vendoring/patches/patched/pip_index_safety.patch
+++ b/tasks/vendoring/patches/patched/pip_index_safety.patch
@@ -36,7 +36,7 @@ index 0120610c..ead5227e 100644
          return link_collector
 
 diff --git a/pipenv/patched/pip/_internal/models/search_scope.py b/pipenv/patched/pip/_internal/models/search_scope.py
-index a64af738..0674ed07 100644
+index a64af738..76c44656 100644
 --- a/pipenv/patched/pip/_internal/models/search_scope.py
 +++ b/pipenv/patched/pip/_internal/models/search_scope.py
 @@ -3,7 +3,7 @@ import logging
@@ -94,4 +94,6 @@ index a64af738..0674ed07 100644
 +        index_urls = self.index_urls
 +        if project_name in self.index_lookup:
 +            index_urls = [self.index_lookup[project_name]]
++        else:
++            index_urls = [self.index_urls[0]]
 +        return [mkurl_pypi_url(url) for url in index_urls]