diff --git a/setup.cfg b/setup.cfg
index a51892f11..c6712bcd7 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -53,9 +53,6 @@ strict_optional = False
 [mypy-pip/_internal/models/format_control]
 strict_optional = False
 
-[mypy-pip/_internal/models/link]
-strict_optional = False
-
 [mypy-pip/_internal/operations/check]
 strict_optional = False
 
diff --git a/src/pip/_internal/models/link.py b/src/pip/_internal/models/link.py
index 378e94797..01983e707 100644
--- a/src/pip/_internal/models/link.py
+++ b/src/pip/_internal/models/link.py
@@ -206,5 +206,8 @@ class Link(KeyBasedCompareMixin):
         """
         if not self.has_hash:
             return False
+        # Assert non-None so mypy knows self.hash_name and self.hash are str.
+        assert self.hash_name is not None
+        assert self.hash is not None
 
         return hashes.is_hash_allowed(self.hash_name, hex_digest=self.hash)