diff --git a/litellm/llms/vertex_ai/common_utils.py b/litellm/llms/vertex_ai/common_utils.py
index 078fce63cc1..ad1e70f2ce2 100644
--- a/litellm/llms/vertex_ai/common_utils.py
+++ b/litellm/llms/vertex_ai/common_utils.py
@@ -534,7 +534,6 @@ def _build_vertex_schema_for_gemini_2(parameters: dict) -> dict:
     """
     valid_schema_fields = set(get_type_hints(Schema).keys())
 
-    parameters = dict(parameters)  # shallow copy to avoid mutating caller's dict
     defs = parameters.pop("$defs", {})
     unpack_defs(parameters, defs)