diff --git a/src/pipecat/services/base_whisper.py b/src/pipecat/services/base_whisper.py
index abe9475dc..eae38be64 100644
--- a/src/pipecat/services/base_whisper.py
+++ b/src/pipecat/services/base_whisper.py
@@ -124,7 +124,7 @@ class BaseWhisperSTTService(SegmentedSTTService):
         base_url: Optional[str] = None,
         language: Optional[Language] = Language.EN,
         prompt: Optional[str] = None,
-        temperature: float = 0.0,
+        temperature: Optional[float] = None,
         **kwargs,
     ):
         super().__init__(**kwargs)
diff --git a/src/pipecat/services/groq.py b/src/pipecat/services/groq.py
index 02a7e5e0f..e72597f06 100644
--- a/src/pipecat/services/groq.py
+++ b/src/pipecat/services/groq.py
@@ -67,7 +67,7 @@ class GroqSTTService(BaseWhisperSTTService):
         base_url: str = "https://api.groq.com/openai/v1",
         language: Optional[Language] = Language.EN,
         prompt: Optional[str] = None,
-        temperature: float = 0.0,
+        temperature: Optional[float] = None,
         **kwargs,
     ):
         super().__init__(
diff --git a/src/pipecat/services/openai.py b/src/pipecat/services/openai.py
index 182488f16..6d9af198f 100644
--- a/src/pipecat/services/openai.py
+++ b/src/pipecat/services/openai.py
@@ -421,7 +421,7 @@ class OpenAISTTService(BaseWhisperSTTService):
         base_url: Optional[str] = None,
         language: Optional[Language] = Language.EN,
         prompt: Optional[str] = None,
-        temperature: float = 0.0,
+        temperature: Optional[float] = None,
         **kwargs,
     ):
         super().__init__(