diff --git a/datahub-actions/setup.py b/datahub-actions/setup.py
index 3ad461f9..8b0cf8fa 100644
--- a/datahub-actions/setup.py
+++ b/datahub-actions/setup.py
@@ -39,7 +39,7 @@ def get_long_description():
     "mypy_extensions>=0.4.3",
     # Actual dependencies.
     "typing-inspect",
-    "pydantic>=1.5.1",
+    "pydantic<2",
     "dictdiffer",
     "ratelimit",
 }