diff --git a/backend/stream_providers.py b/backend/stream_providers.py
index 9b58ac0..c84efe2 100755
--- a/backend/stream_providers.py
+++ b/backend/stream_providers.py
@@ -294,8 +294,11 @@ class SeafileRunner(StreamProvider):
         else:
             stream_data["title"] = json_data.get("filePath")
             stream_data["upstream"] = json_data.get("rawPath")
-            if json_data.get("filePath").lower().endswith(".mp4"):
+            ftype = json_data.get("filePath").lower()
+            if ftype.endswith(".mp4"):
                 stream_data["proxy_ctype"] = "video/mp4"
+            elif ftype.endswith(".webm"):
+                stream_data["proxy_ctype"] = "video/webm"
         return StreamData(**stream_data)