diff --git a/litellm/responses/litellm_completion_transformation/transformation.py b/litellm/responses/litellm_completion_transformation/transformation.py
index 3e605e926f7..75f528d88c0 100644
--- a/litellm/responses/litellm_completion_transformation/transformation.py
+++ b/litellm/responses/litellm_completion_transformation/transformation.py
@@ -2928,7 +2928,7 @@ class LiteLLMCompletionResponsesConfig:
                     "name": typed_tool.get("name") or "",
                     "description": typed_tool.get("description") or "",
                     "parameters": parameters,
-                    "strict": typed_tool.get("strict", False) or False,
+                    **({"strict": typed_tool["strict"]} if "strict" in typed_tool else {}),
                 },
             }
             if tool.get("cache_control"):
diff --git a/tests/unit/responses/litellm_completion_transformation/test_litellm_completion_responses.py b/tests/unit/responses/litellm_completion_transformation/test_litellm_completion_responses.py
index 012926c6cb3..add067c7981 100644
--- a/tests/unit/responses/litellm_completion_transformation/test_litellm_completion_responses.py
+++ b/tests/unit/responses/litellm_completion_transformation/test_litellm_completion_responses.py
@@ -15,6 +15,7 @@ from openai.types.responses.response_function_web_search import (
     ActionSearchSource,
     ResponseFunctionWebSearch,
 )
+from openai.types.responses.tool_param import FunctionToolParam
 from pydantic import TypeAdapter, ValidationError
 
 import litellm
@@ -1699,6 +1700,34 @@ def _chat_response_with_tool_search_call(
 class TestToolTransformation:
     """Test cases for tool transformation from Responses API to Chat Completion format"""
 
+    @pytest.mark.parametrize("strict", [None, False, True])
+    def test_responses_function_tool_preserves_strict_presence(self, strict: bool | None) -> None:
+        tool: Final = cast(
+            FunctionToolParam,
+            {
+                "type": "function",
+                "name": "get_weather",
+                "description": "Look up the weather",
+                "parameters": {"type": "object", "properties": {"city": {"type": "string"}}},
+                **({"strict": strict} if strict is not None else {}),
+            },
+        )
+        chat_tools: Final = LiteLLMCompletionResponsesConfig.transform_responses_api_tools_to_chat_completion_tools(
+            tools=[tool]
+        )[0]
+
+        assert chat_tools == [
+            {
+                "type": "function",
+                "function": {
+                    "name": tool["name"],
+                    "description": tool.get("description"),
+                    "parameters": tool["parameters"],
+                    **({"strict": strict} if strict is not None else {}),
+                },
+            }
+        ]
+
     def test_transform_vertex_ai_tools(self):
         """Test that Vertex AI tools are passed through as-is"""
         from litellm.types.llms.vertex_ai import VertexToolName