diff --git a/tests/tool_use/test_chat_completions.py b/tests/tool_use/test_chat_completions.py
index 07b7933f6..e5bb47587 100644
--- a/tests/tool_use/test_chat_completions.py
+++ b/tests/tool_use/test_chat_completions.py
@@ -6,6 +6,7 @@ import pytest
 
 from .utils import (
     MESSAGES_WITHOUT_TOOLS,
+    SEED,
     WEATHER_TOOL,
     ServerConfig,
     ensure_system_prompt,
@@ -27,6 +28,7 @@ async def test_chat_completion_without_tools(
         max_completion_tokens=150,
         model=model_name,
         logprobs=False,
+        seed=SEED,
     )
     choice = chat_completion.choices[0]
     stop_reason = chat_completion.choices[0].finish_reason
@@ -47,6 +49,7 @@ async def test_chat_completion_without_tools(
         max_completion_tokens=150,
         model=model_name,
         logprobs=False,
+        seed=SEED,
         stream=True,
     )
     chunks: list[str] = []
@@ -97,6 +100,7 @@ async def test_chat_completion_with_tools(
         model=model_name,
         tools=[WEATHER_TOOL],
         logprobs=False,
+        seed=SEED,
     )
     choice = chat_completion.choices[0]
     stop_reason = chat_completion.choices[0].finish_reason
@@ -118,6 +122,7 @@ async def test_chat_completion_with_tools(
         model=model_name,
         logprobs=False,
         tools=[WEATHER_TOOL],
+        seed=SEED,
         stream=True,
     )
 
diff --git a/tests/tool_use/test_parallel_tool_calls.py b/tests/tool_use/test_parallel_tool_calls.py
index 77084ec2d..ed8c80d36 100644
--- a/tests/tool_use/test_parallel_tool_calls.py
+++ b/tests/tool_use/test_parallel_tool_calls.py
@@ -10,6 +10,7 @@ from .utils import (
     MESSAGES_ASKING_FOR_PARALLEL_TOOLS,
     MESSAGES_WITH_PARALLEL_TOOL_RESPONSE,
     SEARCH_TOOL,
+    SEED,
     WEATHER_TOOL,
     ServerConfig,
 )
@@ -39,6 +40,7 @@ async def test_parallel_tool_calls(
         model=model_name,
         tools=[WEATHER_TOOL, SEARCH_TOOL],
         logprobs=False,
+        seed=SEED,
     )
 
     choice = chat_completion.choices[0]
@@ -76,6 +78,7 @@ async def test_parallel_tool_calls(
         max_completion_tokens=200,
         tools=[WEATHER_TOOL, SEARCH_TOOL],
         logprobs=False,
+        seed=SEED,
         stream=True,
     )
 
@@ -166,6 +169,7 @@ async def test_parallel_tool_calls_with_results(
         model=model_name,
         tools=[WEATHER_TOOL, SEARCH_TOOL],
         logprobs=False,
+        seed=SEED,
     )
 
     choice = chat_completion.choices[0]
@@ -184,6 +188,7 @@ async def test_parallel_tool_calls_with_results(
         model=model_name,
         tools=[WEATHER_TOOL, SEARCH_TOOL],
         logprobs=False,
+        seed=SEED,
         stream=True,
     )
 
@@ -229,6 +234,7 @@ async def test_parallel_tool_calls_false(client: openai.AsyncOpenAI):
         model=model_name,
         tools=[WEATHER_TOOL, SEARCH_TOOL],
         logprobs=False,
+        seed=SEED,
         parallel_tool_calls=False,
     )
 
@@ -247,6 +253,7 @@ async def test_parallel_tool_calls_false(client: openai.AsyncOpenAI):
         max_completion_tokens=200,
         tools=[WEATHER_TOOL, SEARCH_TOOL],
         logprobs=False,
+        seed=SEED,
         parallel_tool_calls=False,
         stream=True,
     )
diff --git a/tests/tool_use/test_tool_calls.py b/tests/tool_use/test_tool_calls.py
index 6614b6415..f719a886c 100644
--- a/tests/tool_use/test_tool_calls.py
+++ b/tests/tool_use/test_tool_calls.py
@@ -10,6 +10,7 @@ from .utils import (
     MESSAGES_ASKING_FOR_TOOLS,
     MESSAGES_WITH_TOOL_RESPONSE,
     SEARCH_TOOL,
+    SEED,
     WEATHER_TOOL,
 )
 
@@ -27,6 +28,7 @@ async def test_tool_call_and_choice(client: openai.AsyncOpenAI):
         model=model_name,
         tools=[WEATHER_TOOL, SEARCH_TOOL],
         logprobs=False,
+        seed=SEED,
     )
 
     choice = chat_completion.choices[0]
@@ -71,6 +73,7 @@ async def test_tool_call_and_choice(client: openai.AsyncOpenAI):
         max_completion_tokens=100,
         tools=[WEATHER_TOOL, SEARCH_TOOL],
         logprobs=False,
+        seed=SEED,
         stream=True,
     )
 
@@ -154,6 +157,7 @@ async def test_tool_call_with_results(client: openai.AsyncOpenAI):
         model=model_name,
         tools=[WEATHER_TOOL, SEARCH_TOOL],
         logprobs=False,
+        seed=SEED,
     )
 
     choice = chat_completion.choices[0]
@@ -171,6 +175,7 @@ async def test_tool_call_with_results(client: openai.AsyncOpenAI):
         model=model_name,
         tools=[WEATHER_TOOL, SEARCH_TOOL],
         logprobs=False,
+        seed=SEED,
         stream=True,
     )
 
diff --git a/tests/tool_use/utils.py b/tests/tool_use/utils.py
index de7284a30..5a03f53ec 100644
--- a/tests/tool_use/utils.py
+++ b/tests/tool_use/utils.py
@@ -42,6 +42,8 @@ def ensure_system_prompt(
 
 # universal args for all models go here. also good if you need to test locally
 # and change type or KV cache quantization or something.
+SEED = 42
+
 ARGS: list[str] = [
     "--enable-auto-tool-choice",
     "--max-model-len",