diff --git a/tests/gateway/test_session.py b/tests/gateway/test_session.py
index b5808a99..0737f18d 100644
--- a/tests/gateway/test_session.py
+++ b/tests/gateway/test_session.py
@@ -577,3 +577,28 @@ class TestLastPromptTokens:
 
         store.update_session("k1", last_prompt_tokens=0)
         assert entry.last_prompt_tokens == 0
+
+    def test_update_session_passes_model_to_db(self, tmp_path):
+        """Gateway session updates should forward the resolved model to SQLite."""
+        config = GatewayConfig()
+        with patch("gateway.session.SessionStore._ensure_loaded"):
+            store = SessionStore(sessions_dir=tmp_path, config=config)
+        store._loaded = True
+        store._save = MagicMock()
+        store._db = MagicMock()
+
+        from gateway.session import SessionEntry
+        from datetime import datetime
+        entry = SessionEntry(
+            session_key="k1",
+            session_id="s1",
+            created_at=datetime.now(),
+            updated_at=datetime.now(),
+        )
+        store._entries = {"k1": entry}
+
+        store.update_session("k1", model="openai/gpt-5.4")
+
+        store._db.update_token_counts.assert_called_once_with(
+            "s1", 0, 0, model="openai/gpt-5.4"
+        )
diff --git a/tests/test_hermes_state.py b/tests/test_hermes_state.py
index 329ae6f4..81e922c7 100644
--- a/tests/test_hermes_state.py
+++ b/tests/test_hermes_state.py
@@ -55,13 +55,27 @@ class TestSessionLifecycle:
 
     def test_update_token_counts(self, db):
         db.create_session(session_id="s1", source="cli")
-        db.update_token_counts("s1", input_tokens=100, output_tokens=50)
         db.update_token_counts("s1", input_tokens=200, output_tokens=100)
+        db.update_token_counts("s1", input_tokens=100, output_tokens=50)
 
         session = db.get_session("s1")
         assert session["input_tokens"] == 300
         assert session["output_tokens"] == 150
 
+    def test_update_token_counts_backfills_model_when_null(self, db):
+        db.create_session(session_id="s1", source="telegram")
+        db.update_token_counts("s1", input_tokens=10, output_tokens=5, model="openai/gpt-5.4")
+
+        session = db.get_session("s1")
+        assert session["model"] == "openai/gpt-5.4"
+
+    def test_update_token_counts_preserves_existing_model(self, db):
+        db.create_session(session_id="s1", source="cli", model="anthropic/claude-opus-4.6")
+        db.update_token_counts("s1", input_tokens=10, output_tokens=5, model="openai/gpt-5.4")
+
+        session = db.get_session("s1")
+        assert session["model"] == "anthropic/claude-opus-4.6"
+
     def test_parent_session(self, db):
         db.create_session(session_id="parent", source="cli")
         db.create_session(session_id="child", source="cli", parent_session_id="parent")