diff --git a/google/generativeai/types/content_types.py b/google/generativeai/types/content_types.py
index b9013a9fc..b4a97f7d0 100644
--- a/google/generativeai/types/content_types.py
+++ b/google/generativeai/types/content_types.py
@@ -698,12 +698,25 @@ class FunctionCallingConfigDict(TypedDict):
     allowed_function_names: list[str]
 
 
-FunctionCallingConfigType = Union[FunctionCallingConfigDict, glm.FunctionCallingConfig]
+FunctionCallingConfigType = Union[
+    FunctionCallingModeType, FunctionCallingConfigDict, glm.FunctionCallingConfig
+]
 
 
 def to_function_calling_config(obj: FunctionCallingConfigType) -> glm.FunctionCallingConfig:
-    if isinstance(obj, (FunctionCallingMode, str, int)):
+    if isinstance(obj, glm.FunctionCallingConfig):
+        return obj
+    elif isinstance(obj, (FunctionCallingMode, str, int)):
         obj = {"mode": to_function_calling_mode(obj)}
+    elif isinstance(obj, dict):
+        obj = obj.copy()
+        mode = obj.pop("mode")
+        obj["mode"] = to_function_calling_mode(mode)
+    else:
+        raise TypeError(
+            f"Could not convert input to `glm.FunctionCallingConfig`: \n'" f"  type: {type(obj)}\n",
+            obj,
+        )
 
     return glm.FunctionCallingConfig(obj)
 
diff --git a/tests/test_generative_models.py b/tests/test_generative_models.py
index 4d5488421..a7cdb3ff0 100644
--- a/tests/test_generative_models.py
+++ b/tests/test_generative_models.py
@@ -613,6 +613,99 @@ def test_tools(self):
             self.assertLen(obr.tools, 1)
             self.assertEqual(type(obr.tools[0]).to_dict(obr.tools[0]), tools)
 
+    @parameterized.named_parameters(
+        dict(
+            testcase_name="test_FunctionCallingMode_str",
+            tool_config={"function_calling_config": "any"},
+            expected_tool_config={
+                "function_calling_config": {
+                    "mode": content_types.FunctionCallingMode.ANY,
+                    "allowed_function_names": [],
+                }
+            },
+        ),
+        dict(
+            testcase_name="test_FunctionCallingMode_int",
+            tool_config={"function_calling_config": 1},
+            expected_tool_config={
+                "function_calling_config": {
+                    "mode": content_types.FunctionCallingMode.AUTO,
+                    "allowed_function_names": [],
+                }
+            },
+        ),
+        dict(
+            testcase_name="test_FunctionCallingMode",
+            tool_config={"function_calling_config": content_types.FunctionCallingMode.NONE},
+            expected_tool_config={
+                "function_calling_config": {
+                    "mode": content_types.FunctionCallingMode.NONE,
+                    "allowed_function_names": [],
+                }
+            },
+        ),
+        dict(
+            testcase_name="test_glm_FunctionCallingConfig",
+            tool_config={
+                "function_calling_config": glm.FunctionCallingConfig(
+                    mode=content_types.FunctionCallingMode.AUTO
+                )
+            },
+            expected_tool_config={
+                "function_calling_config": {
+                    "mode": content_types.FunctionCallingMode.AUTO,
+                    "allowed_function_names": [],
+                }
+            },
+        ),
+        dict(
+            testcase_name="test_FunctionCallingConfigDict",
+            tool_config={
+                "function_calling_config": {
+                    "mode": "mode_auto",
+                    "allowed_function_names": ["datetime", "greetings", "random"],
+                }
+            },
+            expected_tool_config={
+                "function_calling_config": {
+                    "mode": content_types.FunctionCallingMode.AUTO,
+                    "allowed_function_names": ["datetime", "greetings", "random"],
+                }
+            },
+        ),
+        dict(
+            testcase_name="test_glm_ToolConfig",
+            tool_config=glm.ToolConfig(
+                function_calling_config=glm.FunctionCallingConfig(
+                    mode=content_types.FunctionCallingMode.NONE
+                )
+            ),
+            expected_tool_config={
+                "function_calling_config": {
+                    "mode": content_types.FunctionCallingMode.NONE,
+                    "allowed_function_names": [],
+                }
+            },
+        ),
+    )
+    def test_tool_config(self, tool_config, expected_tool_config):
+        tools = dict(
+            function_declarations=[
+                dict(name="datetime", description="Returns the current UTC date and time."),
+                dict(name="greetings", description="Returns a greeting."),
+                dict(name="random", description="Returns a random number."),
+            ]
+        )
+        self.responses["generate_content"] = [simple_response("echo echo")]
+
+        model = generative_models.GenerativeModel("gemini-pro", tools=tools)
+        _ = model.generate_content("Hello", tools=[tools], tool_config=tool_config)
+
+        req = self.observed_requests[0]
+
+        self.assertLen(type(req.tools[0]).to_dict(req.tools[0]).get("function_declarations"), 3)
+        self.assertEqual(type(req.tool_config).to_dict(req.tool_config), expected_tool_config)
+
     @parameterized.named_parameters(
         ["bare_str", "talk like a pirate", simple_part("talk like a pirate")],
         [
diff --git a/tests/test_generative_models_async.py b/tests/test_generative_models_async.py
index 6b30b04fc..8a93c2295 100644
--- a/tests/test_generative_models_async.py
+++ b/tests/test_generative_models_async.py
@@ -23,6 +23,7 @@
 
 from google.generativeai import client as client_lib
 from google.generativeai import generative_models
+from google.generativeai.types import content_types
 import google.ai.generativelanguage as glm
 
 from absl.testing import absltest
@@ -107,6 +108,99 @@ async def responses():
 
         self.assertEqual(response.text, "world!")
 
+    @parameterized.named_parameters(
+        dict(
+            testcase_name="test_FunctionCallingMode_str",
+            tool_config={"function_calling_config": "any"},
+            expected_tool_config={
+                "function_calling_config": {
+                    "mode": content_types.FunctionCallingMode.ANY,
+                    "allowed_function_names": [],
+                }
+            },
+        ),
+        dict(
+            testcase_name="test_FunctionCallingMode_int",
+            tool_config={"function_calling_config": 1},
+            expected_tool_config={
+                "function_calling_config": {
+                    "mode": content_types.FunctionCallingMode.AUTO,
+                    "allowed_function_names": [],
+                }
+            },
+        ),
+        dict(
+            testcase_name="test_FunctionCallingMode",
+            tool_config={"function_calling_config": content_types.FunctionCallingMode.NONE},
+            expected_tool_config={
+                "function_calling_config": {
+                    "mode": content_types.FunctionCallingMode.NONE,
+                    "allowed_function_names": [],
+                }
+            },
+        ),
+        dict(
+            testcase_name="test_glm_FunctionCallingConfig",
+            tool_config={
+                "function_calling_config": glm.FunctionCallingConfig(
+                    mode=content_types.FunctionCallingMode.AUTO
+                )
+            },
+            expected_tool_config={
+                "function_calling_config": {
+                    "mode": content_types.FunctionCallingMode.AUTO,
+                    "allowed_function_names": [],
+                }
+            },
+        ),
+        dict(
+            testcase_name="test_FunctionCallingConfigDict",
+            tool_config={
+                "function_calling_config": {
+                    "mode": "mode_auto",
+                    "allowed_function_names": ["datetime", "greetings", "random"],
+                }
+            },
+            expected_tool_config={
+                "function_calling_config": {
+                    "mode": content_types.FunctionCallingMode.AUTO,
+                    "allowed_function_names": ["datetime", "greetings", "random"],
+                }
+            },
+        ),
+        dict(
+            testcase_name="test_glm_ToolConfig",
+            tool_config=glm.ToolConfig(
+                function_calling_config=glm.FunctionCallingConfig(
+                    mode=content_types.FunctionCallingMode.NONE
+                )
+            ),
+            expected_tool_config={
+                "function_calling_config": {
+                    "mode": content_types.FunctionCallingMode.NONE,
+                    "allowed_function_names": [],
+                }
+            },
+        ),
+    )
+    async def test_tool_config(self, tool_config, expected_tool_config):
+        tools = dict(
+            function_declarations=[
+                dict(name="datetime", description="Returns the current UTC date and time."),
+                dict(name="greetings", description="Returns a greeting."),
+                dict(name="random", description="Returns a random number."),
+            ]
+        )
+        self.responses["generate_content"] = [simple_response("echo echo")]
+
+        model = generative_models.GenerativeModel("gemini-pro", tools=tools)
+        _ = await model.generate_content_async("Hello", tools=[tools], tool_config=tool_config)
+
+        req = self.observed_requests[0]
+
+        self.assertLen(type(req.tools[0]).to_dict(req.tools[0]).get("function_declarations"), 3)
+        self.assertEqual(type(req.tool_config).to_dict(req.tool_config), expected_tool_config)
+
     @parameterized.named_parameters(
         ["basic", "Hello"],
         ["list", ["Hello"]],