diff --git a/packages/openpi-client/pyproject.toml b/packages/openpi-client/pyproject.toml
index fba7b66f62..4b63f6c0db 100644
--- a/packages/openpi-client/pyproject.toml
+++ b/packages/openpi-client/pyproject.toml
@@ -8,6 +8,7 @@ dependencies = [
     "numpy>=1.22.4,<2.0.0",
     "pillow>=9.0.0",
     "tree>=0.2.4",
+    "typing-extensions>=4.12.2",
     "websockets>=11.0",
 ]