diff --git a/tests/test_openrouter_model_selection.py b/tests/test_openrouter_model_selection.py
index 5b832e81..dba5b131 100644
--- a/tests/test_openrouter_model_selection.py
+++ b/tests/test_openrouter_model_selection.py
@@ -19,6 +19,31 @@ class OpenRouterModelSelectionTests(unittest.TestCase):
         )
         self.assertEqual(chosen, "minimax/minimax-m2.1")
 
+    def test_exit_on_no_choice(self):
+        with self.assertRaises(SystemExit) as cm:
+            resolve_model_choice("openrouter", None, "Quick-Thinking")
+        self.assertEqual(cm.exception.code, 1)
+
+    def test_exit_on_empty_custom_model_input(self):
+        with self.assertRaises(SystemExit) as cm:
+            resolve_model_choice(
+                "openrouter",
+                CUSTOM_OPENROUTER_MODEL,
+                "Deep-Thinking",
+                prompt_fn=lambda _: "   ",
+            )
+        self.assertEqual(cm.exception.code, 1)
+
+    def test_exit_on_none_custom_model_input(self):
+        with self.assertRaises(SystemExit) as cm:
+            resolve_model_choice(
+                "openrouter",
+                CUSTOM_OPENROUTER_MODEL,
+                "Deep-Thinking",
+                prompt_fn=lambda _: None,
+            )
+        self.assertEqual(cm.exception.code, 1)
+
 
 if __name__ == "__main__":
     unittest.main()