diff --git a/tests/test_encoder.py b/tests/test_encoder.py
index 9c53e57..5d810b7 100644
--- a/tests/test_encoder.py
+++ b/tests/test_encoder.py
@@ -9,7 +9,7 @@ from torchscale.architecture.encoder import Encoder
 
 testcases = [
     {},
-    {"vocab_size": 64000},
+    {"vocab_size": 32000},
     {"activation_fn": "relu"},
     {"drop_path_rate": 0.1},
     {"encoder_normalize_before": False},