diff --git a/testing/web-platform/tests/interfaces/web-share.idl b/testing/web-platform/tests/interfaces/web-share.idl
index e275aac96fe9..ae1f3f8580c0 100644
--- a/testing/web-platform/tests/interfaces/web-share.idl
+++ b/testing/web-platform/tests/interfaces/web-share.idl
@@ -3,6 +3,10 @@
 // (https://github.com/tidoust/reffy-reports)
 // Source: Web Share API - Level 1 (https://wicg.github.io/web-share/)
 
+partial interface Navigator {
+  [SecureContext] Promise<void> share(optional ShareData data = {});
+};
+
 dictionary ShareData {
   USVString title;
   USVString text;