diff --git a/servers/fastapi/services/llm_client.py b/servers/fastapi/services/llm_client.py
index 448a94b5..ce86f6db 100644
--- a/servers/fastapi/services/llm_client.py
+++ b/servers/fastapi/services/llm_client.py
@@ -387,7 +387,11 @@ class LLMClient:
         max_tokens: Optional[int] = None,
         depth: int = 0,
     ):
-        extra_body = {"enable_thinking": not self.disable_thinking()}
+        extra_body = (
+            {"enable_thinking": False}
+            if self.disable_thinking()
+            else None
+        )
         return await self._generate_openai(
             model=model,
             messages=messages,
@@ -754,7 +758,11 @@ class LLMClient:
         max_tokens: Optional[int] = None,
         depth: int = 0,
     ):
-        extra_body = {"enable_thinking": not self.disable_thinking()}
+        extra_body = (
+            {"enable_thinking": False}
+            if self.disable_thinking()
+            else None
+        )
         return await self._generate_openai_structured(
             model=model,
             messages=messages,
@@ -1071,7 +1079,11 @@ class LLMClient:
         max_tokens: Optional[int] = None,
         depth: int = 0,
     ):
-        extra_body = {"enable_thinking": not self.disable_thinking()}
+        extra_body = (
+            {"enable_thinking": False}
+            if self.disable_thinking()
+            else None
+        )
         return self._stream_openai(
             model=model,
             messages=messages,
@@ -1484,7 +1496,11 @@ class LLMClient:
         max_tokens: Optional[int] = None,
         depth: int = 0,
     ):
-        extra_body = {"enable_thinking": not self.disable_thinking()}
+        extra_body = (
+            {"enable_thinking": False}
+            if self.disable_thinking()
+            else None
+        )
         return self._stream_openai_structured(
             model=model,
             messages=messages,