diff --git a/pyproject.toml b/pyproject.toml
index 8df936f807..d56bdc105e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -40,7 +40,7 @@ huggingface = [
     "unsloth_zoo>=2025.9.6",
     "packaging",
     "tyro",
-    "transformers>=4.51.3,!=4.52.0,!=4.52.1,!=4.52.2,!=4.52.3,!=4.53.0,!=4.54.0,!=4.55.0,!=4.55.1",
+    "transformers>=4.51.3,!=4.52.0,!=4.52.1,!=4.52.2,!=4.52.3,!=4.53.0,!=4.54.0,!=4.55.0,!=4.55.1,<=4.55.4",
     "datasets>=3.4.1,<4.0.0",
     "sentencepiece>=0.2.0",
     "tqdm",
@@ -456,7 +456,7 @@ colab-new = [
     "unsloth_zoo>=2025.9.6",
     "packaging",
     "tyro",
-    "transformers>=4.51.3,!=4.47.0,!=4.52.0,!=4.52.1,!=4.52.2,!=4.52.3,!=4.53.0,!=4.54.0,!=4.55.0,!=4.55.1",
+    "transformers>=4.51.3,!=4.47.0,!=4.52.0,!=4.52.1,!=4.52.2,!=4.52.3,!=4.53.0,!=4.54.0,!=4.55.0,!=4.55.1,<=4.55.4",
     "datasets>=3.4.1,<4.0.0",
     "sentencepiece>=0.2.0",
     "tqdm",