diff --git a/lbrynet/extras/daemon/mime_types.py b/lbrynet/extras/daemon/mime_types.py
index df182d2c2..c9f38ee7d 100644
--- a/lbrynet/extras/daemon/mime_types.py
+++ b/lbrynet/extras/daemon/mime_types.py
@@ -154,5 +154,5 @@ types_map = {
 
 def guess_media_type(path):
     _, ext = os.path.splitext(path)
-    default = f'application/x-ext-{ext}' if ext else 'application/octet-stream'
+    default = 'application/octet-stream' if not ext else f'application/x-ext-{ext[1:].strip().lower()}'
     return types_map.get(ext, default)