diff --git a/libs/partners/openai/langchain_openai/chat_models/base.py b/libs/partners/openai/langchain_openai/chat_models/base.py
index 478a42a0810..2ed4403550a 100644
--- a/libs/partners/openai/langchain_openai/chat_models/base.py
+++ b/libs/partners/openai/langchain_openai/chat_models/base.py
@@ -562,6 +562,7 @@ _RESPONSES_API_ONLY_PREFIXES = (
     "gpt-5-pro",
     "gpt-5.2-pro",
     "gpt-5.4-pro",
+    "gpt-5.5-pro",
 )