diff --git a/src/flask/sessions.py b/src/flask/sessions.py
index 254390d7..5bd8891e 100644
--- a/src/flask/sessions.py
+++ b/src/flask/sessions.py
@@ -295,9 +295,6 @@ class SessionInterface:
                 self.sessions.append(new_session)
                 return 1
 
-            if number_of_sessions == len(self.sessions):
-                return None
-
         return len(self.sessions)