diff --git a/autogen/agentchat/conversable_agent.py b/autogen/agentchat/conversable_agent.py
index 89b2dd94345..c3394a96bb6 100644
--- a/autogen/agentchat/conversable_agent.py
+++ b/autogen/agentchat/conversable_agent.py
@@ -2406,6 +2406,8 @@ def register_function(self, function_map: Dict[str, Union[Callable, None]]):
             self._assert_valid_name(name)
             if func is None and name not in self._function_map.keys():
                 warnings.warn(f"The function {name} to remove doesn't exist", name)
+            if name in self._function_map:
+                warnings.warn(f"Function '{name}' is being overridden.", UserWarning)
         self._function_map.update(function_map)
         self._function_map = {k: v for k, v in self._function_map.items() if v is not None}
 
@@ -2442,6 +2444,9 @@ def update_function_signature(self, func_sig: Union[str, Dict], is_remove: None)
 
             self._assert_valid_name(func_sig["name"])
             if "functions" in self.llm_config.keys():
+                if any(func["name"] == func_sig["name"] for func in self.llm_config["functions"]):
+                    warnings.warn(f"Function '{func_sig['name']}' is being overridden.", UserWarning)
+
                 self.llm_config["functions"] = [
                     func for func in self.llm_config["functions"] if func.get("name") != func_sig["name"]
                 ] + [func_sig]
@@ -2481,7 +2486,9 @@ def update_tool_signature(self, tool_sig: Union[str, Dict], is_remove: None):
                     f"The tool signature must be of the type dict. Received tool signature type {type(tool_sig)}"
                 )
             self._assert_valid_name(tool_sig["function"]["name"])
-            if "tools" in self.llm_config.keys():
+            if "tools" in self.llm_config:
+                if any(tool["function"]["name"] == tool_sig["function"]["name"] for tool in self.llm_config["tools"]):
+                    warnings.warn(f"Function '{tool_sig['function']['name']}' is being overridden.", UserWarning)
                 self.llm_config["tools"] = [
                     tool
                     for tool in self.llm_config["tools"]
diff --git a/test/agentchat/test_conversable_agent.py b/test/agentchat/test_conversable_agent.py
index b81a897b47c..3c2e79beb13 100755
--- a/test/agentchat/test_conversable_agent.py
+++ b/test/agentchat/test_conversable_agent.py
@@ -1403,6 +1403,64 @@ def test_http_client():
         )
 
 
+def test_adding_duplicate_function_warning():
+
+    config_base = [{"base_url": "http://0.0.0.0:8000", "api_key": "NULL"}]
+
+    agent = autogen.ConversableAgent(
+        "jtoy",
+        llm_config={"config_list": config_base},
+    )
+
+    def sample_function():
+        pass
+
+    agent.register_function(
+        function_map={
+            "sample_function": sample_function,
+        }
+    )
+    agent.update_function_signature(
+        {
+            "name": "foo",
+        },
+        is_remove=False,
+    )
+    agent.update_tool_signature(
+        {
+            "type": "function",
+            "function": {
+                "name": "yo",
+            },
+        },
+        is_remove=False,
+    )
+
+    with pytest.warns(UserWarning, match="Function 'sample_function' is being overridden."):
+        agent.register_function(
+            function_map={
+                "sample_function": sample_function,
+            }
+        )
+    with pytest.warns(UserWarning, match="Function 'foo' is being overridden."):
+        agent.update_function_signature(
+            {
+                "name": "foo",
+            },
+            is_remove=False,
+        )
+    with pytest.warns(UserWarning, match="Function 'yo' is being overridden."):
+        agent.update_tool_signature(
+            {
+                "type": "function",
+                "function": {
+                    "name": "yo",
+                },
+            },
+            is_remove=False,
+        )
+
+
 if __name__ == "__main__":
     # test_trigger()
     # test_context()
@@ -1414,4 +1472,5 @@ def test_http_client():
     # test_process_before_send()
     # test_message_func()
     test_summary()
+    test_adding_duplicate_function_warning()
     # test_function_registration_e2e_sync()