diff --git a/tests/test_client.py b/tests/test_client.py
index 34657513..657603b1 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -134,7 +134,7 @@ def generate():
 
   it = iter(['I ', "don't ", 'know.'])
   for part in response:
-    assert part['message']['role'] in 'assistant'
+    assert part['message']['role'] == 'assistant'
     assert part['message']['content'] == next(it)