diff --git a/pyproject.toml b/pyproject.toml
index e7ed394..eea9ba3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -24,7 +24,7 @@ dependencies = [
     "torch>=2.1",
     # transformer_lens upper pin is conservative: TL has had breaking
     # changes in past majors. Loosen when TL 3.x ships and is validated.
-    "transformer_lens>=2.0,<3.0",
+    "transformer_lens>=3.2.1,<4.0",
     "datasets",
     "accelerate",
     "click>=8.4.0",