diff --git a/botocore/endpoint_provider.py b/botocore/endpoint_provider.py
index 9439086c53..38b0a5ffe6 100644
--- a/botocore/endpoint_provider.py
+++ b/botocore/endpoint_provider.py
@@ -638,7 +638,7 @@ def process_input(self, value):
                 return self.default
             if self.required:
                 raise EndpointResolutionError(
-                    f"Cannot find value for required parameter {self.name}"
+                    msg=f"Cannot find value for required parameter {self.name}"
                 )
             # in all other cases, the parameter will keep the value None
         else: