diff --git a/tests/test-tokenizer-random.py b/tests/test-tokenizer-random.py
index 93da1d21f..7d84ff554 100644
--- a/tests/test-tokenizer-random.py
+++ b/tests/test-tokenizer-random.py
@@ -423,7 +423,7 @@ def compare_tokenizers(tokenizer1: TokenizerGroundtruth, tokenizer2: TokenizerLl
         #         return -1
         #     return min(len(ids1), len(ids2))
         # Rewritten to use zip() and next() instead of for loop
-        def find_first_mismatch(ids1, ids2) -> int:
+        def find_first_mismatch(ids1: Sequence[Any], ids2: Sequence[Any]) -> int:
             index = next((i for i, (a, b) in enumerate(zip(ids1, ids2)) if a != b), -1)
             if index < 0 and len(ids1) != len(ids2):
                 index = min(len(ids1), len(ids2))