1 files changed, 1 insertions, 0 deletions
diff --git a/components/script/dom/request.rs b/components/script/dom/request.rs
index 8ca9104b945..2b26d5e1e8c 100644
--- a/components/script/dom/request.rs
+++ b/components/script/dom/request.rs
@@ -826,6 +826,7 @@ impl Into<RequestMode> for NetTraitsRequestMode {
             NetTraitsRequestMode::SameOrigin => RequestMode::Same_origin,
             NetTraitsRequestMode::NoCors => RequestMode::No_cors,
             NetTraitsRequestMode::CorsMode => RequestMode::Cors,
+            NetTraitsRequestMode::WebSocket => unreachable!("Websocket request mode should never be exposed to JS"),
         }
     }
 }