diff --git a/.changeset/rare-wolves-deliver.md b/.changeset/rare-wolves-deliver.md
new file mode 100644
index 000000000000..a9a669e5edc7
--- /dev/null
+++ b/.changeset/rare-wolves-deliver.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-vercel': patch
+---
+
+Fix `global is not defined` runtime error building with `edge: true` option
diff --git a/packages/adapter-vercel/index.js b/packages/adapter-vercel/index.js
index 0d0ba443385c..37027c836f7a 100644
--- a/packages/adapter-vercel/index.js
+++ b/packages/adapter-vercel/index.js
@@ -189,7 +189,8 @@ export default function ({ external = [], edge, split } = {}) {
 					platform: 'browser',
 					format: 'esm',
 					external,
-					sourcemap: 'linked'
+					sourcemap: 'linked',
+					banner: { js: 'globalThis.global = globalThis;' }
 				});
 
 				write(