diff --git a/VoidCat/Controllers/UploadController.cs b/VoidCat/Controllers/UploadController.cs
index acd5f51..252fd76 100644
--- a/VoidCat/Controllers/UploadController.cs
+++ b/VoidCat/Controllers/UploadController.cs
@@ -73,6 +73,11 @@ namespace VoidCat.Controllers
                     }
                 }
 
+                if (string.IsNullOrEmpty(mime))
+                {
+                    mime = "application/octet-stream";
+                }
+
                 // detect store for ingress
                 var store = _settings.DefaultFileStore;
                 if (uid.HasValue)