diff --git a/lib/wpt/index.js b/lib/wpt/index.js
index 601b207b..1e55a371 100644
--- a/lib/wpt/index.js
+++ b/lib/wpt/index.js
@@ -222,7 +222,7 @@ export class InterfacesUpdater extends WPTUpdater {
     const found = [];
     for (const mod of supported) {
       const idl = `${mod}.idl`;
-      const asset = assets.find(asset => asset.name === idl);
+      const asset = assets.find(asset => asset.name.toLowerCase() === idl.toLowerCase());
       if (asset) {
         found.push(asset);
       } else {