diff --git a/libs/langchain/tests/unit_tests/chains/rl_chain/test_rl_chain_base_embedder.py b/libs/langchain/tests/unit_tests/chains/rl_chain/test_rl_chain_base_embedder.py
index c9f8416ceb7ec..7402c64d381b0 100644
--- a/libs/langchain/tests/unit_tests/chains/rl_chain/test_rl_chain_base_embedder.py
+++ b/libs/langchain/tests/unit_tests/chains/rl_chain/test_rl_chain_base_embedder.py
@@ -116,7 +116,8 @@ def test_simple_action_strlist_no_emb() -> None:
     str2 = "test2"
     str3 = "test3"
     expected = [{"a_namespace": str1}, {"a_namespace": str2}, {"a_namespace": str3}]
-    assert base.embed([str1, str2, str3], MockEncoder(), "a_namespace") == expected
+    to_embed: List[str] = [str1, str2, str3]
+    assert base.embed(to_embed, MockEncoder(), "a_namespace") == expected
 
 
 @pytest.mark.requires("vowpal_wabbit_next")