diff --git a/tests/test_e2e.py b/tests/test_e2e.py
index 5d115f6..604452a 100644
--- a/tests/test_e2e.py
+++ b/tests/test_e2e.py
@@ -404,6 +404,11 @@ class TestCodexLaunch:
     CODEX_INCOMPATIBLE_MODEL_FRAGMENTS = (
         # nano endpoint is unreliably slow and times out past the 60s budget.
         "gpt-5-4-nano",
+        # These endpoints are discoverable as responses-capable, but the
+        # backing OpenAI endpoint returns ENDPOINT_NOT_FOUND in the CI region.
+        "gpt-5-6-luna",
+        "gpt-5-6-sol",
+        "gpt-5-6-terra",
     )
 
     def _codex_models(self, e2e_state: dict) -> list[str]:
@@ -812,6 +817,8 @@ class TestCopilotLaunch:
         # gpt-5.5 rejects function tools + reasoning_effort on /chat/completions
         # ("Please use /v1/responses instead").
         "gpt-5-5",
+        # gpt-5.6 models similarly reject /chat/completions with 404.
+        "gpt-5-6",
     )
 
     def _all_models(self, e2e_state: dict) -> list[tuple[str, str]]: