diff --git a/backend/open_webui/routers/audio.py b/backend/open_webui/routers/audio.py
index 6baaa589d..211f2ae85 100644
--- a/backend/open_webui/routers/audio.py
+++ b/backend/open_webui/routers/audio.py
@@ -920,14 +920,18 @@ def transcription(
 ):
     log.info(f"file.content_type: {file.content_type}")
 
-    supported_content_types = request.app.state.config.STT_SUPPORTED_CONTENT_TYPES or [
-        "audio/*",
-        "video/webm",
-    ]
+    stt_supported_content_types = getattr(
+        request.app.state.config, "STT_SUPPORTED_CONTENT_TYPES", []
+    )
 
     if not any(
         fnmatch(file.content_type, content_type)
-        for content_type in supported_content_types
+        for content_type in (
+            stt_supported_content_types
+            if stt_supported_content_types
+            and any(t.strip() for t in stt_supported_content_types)
+            else ["audio/*", "video/webm"]
+        )
     ):
         raise HTTPException(
             status_code=status.HTTP_400_BAD_REQUEST,
diff --git a/backend/open_webui/routers/files.py b/backend/open_webui/routers/files.py
index b9bb15c7b..bdf5780fc 100644
--- a/backend/open_webui/routers/files.py
+++ b/backend/open_webui/routers/files.py
@@ -155,17 +155,18 @@ def upload_file(
         if process:
             try:
                 if file.content_type:
-                    stt_supported_content_types = (
-                        request.app.state.config.STT_SUPPORTED_CONTENT_TYPES
-                        or [
-                            "audio/*",
-                            "video/webm",
-                        ]
+                    stt_supported_content_types = getattr(
+                        request.app.state.config, "STT_SUPPORTED_CONTENT_TYPES", []
                     )
 
                     if any(
                         fnmatch(file.content_type, content_type)
-                        for content_type in stt_supported_content_types
+                        for content_type in (
+                            stt_supported_content_types
+                            if stt_supported_content_types
+                            and any(t.strip() for t in stt_supported_content_types)
+                            else ["audio/*", "video/webm"]
+                        )
                     ):
                         file_path = Storage.get_file(file_path)
                         result = transcribe(request, file_path, file_metadata)