diff --git a/polyfill.js b/polyfill.js
index 3ca8923..5d31048 100644
--- a/polyfill.js
+++ b/polyfill.js
@@ -6,6 +6,7 @@ const ac = require("./dist/abort-controller")
 /*eslint-disable @mysticatea/prettier */
 const g =
     typeof self !== "undefined" ? self :
+    typeof globalThis !== "undefined" ? globalThis :
     typeof window !== "undefined" ? window :
     typeof global !== "undefined" ? global :
     /* otherwise */ undefined
diff --git a/polyfill.mjs b/polyfill.mjs
index 0602a64..2a1a9d2 100644
--- a/polyfill.mjs
+++ b/polyfill.mjs
@@ -4,6 +4,7 @@ import * as ac from "./dist/abort-controller"
 /*eslint-disable @mysticatea/prettier */
 const g =
     typeof self !== "undefined" ? self :
+    typeof globalThis !== "undefined" ? globalThis :
     typeof window !== "undefined" ? window :
     typeof global !== "undefined" ? global :
     /* otherwise */ undefined