diff --git a/pyproject.toml b/pyproject.toml
index 3f63f56..14fa6c1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,7 +16,7 @@ dependencies = [
     "PyPcre>=0.2.15",
     "PyYAML>=6.0",
     "sacrebleu>=2.6.0",
-    "transformers>=5.3.0",
+    "transformers>=5.3.0,<5.6.0",
     "maturin",
 ]
 classifiers = [