diff --git a/Startup.cs b/Startup.cs
index 42210d1..f653d2c 100644
--- a/Startup.cs
+++ b/Startup.cs
@@ -42,6 +42,7 @@ namespace webmusic
             var provider = new FileExtensionContentTypeProvider();
             provider.Mappings[".flac"] = "audio/flac";
             provider.Mappings[".m3u"] = "audio/m3u";
+            provider.Mappings[".opus"] = "audio/opus";
             if (env.IsDevelopment())
             {
                 app.UseDeveloperExceptionPage();