diff --git a/backend/open_webui/routers/audio.py b/backend/open_webui/routers/audio.py
index 0816cdcde3..120300d49e 100644
--- a/backend/open_webui/routers/audio.py
+++ b/backend/open_webui/routers/audio.py
@@ -1151,10 +1151,9 @@ def transcription(
     user=Depends(get_verified_user),
 ):
     log.info(f"file.content_type: {file.content_type}")
-
     stt_supported_content_types = getattr(
         request.app.state.config, "STT_SUPPORTED_CONTENT_TYPES", []
-    ) or ["audio/*", "video/webm"]
+    )
 
     if not strict_match_mime_type(stt_supported_content_types, file.content_type):
         raise HTTPException(
diff --git a/backend/open_webui/routers/files.py b/backend/open_webui/routers/files.py
index 723a150197..7f01537e66 100644
--- a/backend/open_webui/routers/files.py
+++ b/backend/open_webui/routers/files.py
@@ -114,7 +114,7 @@ def process_uploaded_file(request, file, file_path, file_item, file_metadata, us
         if file.content_type:
             stt_supported_content_types = getattr(
                 request.app.state.config, "STT_SUPPORTED_CONTENT_TYPES", []
-            ) or ["audio/*", "video/webm"]
+            )
 
             if strict_match_mime_type(stt_supported_content_types, file.content_type):
                 file_path = Storage.get_file(file_path)
diff --git a/backend/open_webui/utils/misc.py b/backend/open_webui/utils/misc.py
index 85f47719b6..e293f3d257 100644
--- a/backend/open_webui/utils/misc.py
+++ b/backend/open_webui/utils/misc.py
@@ -622,6 +622,10 @@ def strict_match_mime_type(supported: list[str] | str, header: str) -> Optional[
 
         supported = [s for s in supported if s.strip() and "/" in s]
 
+        if len(supported) == 0:
+            # Default to common types if none are specified
+            supported = ["audio/*", "video/webm"]
+
         match = mimeparse.best_match(supported, header)
         if not match:
             return None