diff --git a/skillopt_sleep/backend.py b/skillopt_sleep/backend.py
index 768a4e8..fda126d 100644
--- a/skillopt_sleep/backend.py
+++ b/skillopt_sleep/backend.py
@@ -1311,8 +1311,12 @@ class AzureOpenAIBackend(CliBackend):
 
     def _is_azure_host(self) -> bool:
         from urllib.parse import urlparse
-        host = (urlparse(self.endpoint).hostname or "").lower()
-        return host.endswith(self._AZURE_HOST_SUFFIXES)
+        parsed = urlparse(self.endpoint)
+        host = (parsed.hostname or "").lower()
+        return (
+            parsed.scheme.lower() == "https"
+            and host.endswith(self._AZURE_HOST_SUFFIXES)
+        )
 
     def _get_client(self):
         if self._client is None:
@@ -1383,7 +1387,7 @@ class AzureOpenAIBackend(CliBackend):
                     kwargs["max_tokens"] = self.compat_max_tokens
                 else:
                     kwargs["max_completion_tokens"] = 16384
-                if self.chat_extra_body:
+                if self._compat_mode() and self.chat_extra_body:
                     kwargs["extra_body"] = self.chat_extra_body
                 resp = client.chat.completions.create(**kwargs)
                 text = (resp.choices[0].message.content or "").strip()
diff --git a/tests/test_azure_openai_compat.py b/tests/test_azure_openai_compat.py
index bc4e610..cd9d288 100644
--- a/tests/test_azure_openai_compat.py
+++ b/tests/test_azure_openai_compat.py
@@ -108,6 +108,17 @@ class TestClientSelection(unittest.TestCase):
                 be._get_client()
         self.assertIn("openai_compatible", str(ctx.exception))
 
+    def test_managed_identity_refuses_insecure_azure_endpoint(self):
+        # A matching Azure hostname is insufficient: AAD bearer credentials
+        # must never be sent over plaintext HTTP.
+        env = {"AZURE_OPENAI_ENDPOINT": "http://foo.openai.azure.com"}
+        with mock.patch.dict(os.environ, env, clear=True):
+            be = AzureOpenAIBackend(deployment="some-model")
+            self.assertFalse(be._is_azure_host())
+            with self.assertRaises(ValueError) as ctx:
+                be._get_client()
+        self.assertIn("openai_compatible", str(ctx.exception))
+
     def test_azure_host_detection(self):
         with mock.patch.dict(os.environ, {}, clear=True):
             be = AzureOpenAIBackend(deployment="gpt-5.5")  # table endpoint
@@ -189,6 +200,15 @@ class TestRequestKwargs(unittest.TestCase):
         self.assertEqual(call["max_completion_tokens"], 16384)
         self.assertNotIn("max_tokens", call)
 
+    def test_azure_mode_ignores_compat_extra_body(self):
+        body = {"thinking": {"type": "enabled"}}
+        env = {"SKILLOPT_SLEEP_CHAT_EXTRA_BODY": json.dumps(body)}
+        be = _backend_with(["hi"], env)
+        with mock.patch.dict(os.environ, env, clear=True):
+            be._call("p", retries=1)
+        (call,) = be._client.chat.completions.calls
+        self.assertNotIn("extra_body", call)
+
 
 class TestErrorState(unittest.TestCase):
     def test_recovered_retry_clears_last_call_error(self):