diff --git a/py/generate.py b/py/generate.py
index f1b35bd274883..9495b9a92b7f9 100644
--- a/py/generate.py
+++ b/py/generate.py
@@ -233,7 +233,7 @@ def py_annotation(self):
                 py_ref = ref_to_python(self.items.ref)
                 ann = f"typing.List[{py_ref}]"
             else:
-                ann = "typing.List[{}]".format(CdpPrimitiveType.get_annotation(self.items.type))
+                ann = f"typing.List[{CdpPrimitiveType.get_annotation(self.items.type)}]"
         else:
             if self.ref:
                 py_ref = ref_to_python(self.ref)