diff --git a/fastapi/routing.py b/fastapi/routing.py
index d7a585df1..6e04629ce 100644
--- a/fastapi/routing.py
+++ b/fastapi/routing.py
@@ -351,7 +351,7 @@ def get_request_handler(
                         else:
                             body = body_bytes
         except json.JSONDecodeError as e:
-            validation_error = RequestMalformedError(
+            raise RequestMalformedError(
                 [
                     {
                         "type": "json_invalid",
@@ -362,8 +362,7 @@ def get_request_handler(
                     }
                 ],
                 body=e.doc,
-            )
-            raise validation_error from e
+            ) from e
         except HTTPException:
             # If a middleware raises an HTTPException, it should be raised again
             raise