diff --git a/packages/vitest/src/integrations/env/happy-dom.ts b/packages/vitest/src/integrations/env/happy-dom.ts
index fcab5fff7585..21936fafe990 100644
--- a/packages/vitest/src/integrations/env/happy-dom.ts
+++ b/packages/vitest/src/integrations/env/happy-dom.ts
@@ -14,7 +14,6 @@ export default <Environment>({
 
     // TODO: browser doesn't expose Buffer, but a lot of dependencies use it
     win.Buffer = Buffer
-    win.Uint8Array = Uint8Array
 
     // inject structuredClone if it exists
     if (typeof structuredClone !== 'undefined' && !win.structuredClone)
@@ -24,8 +23,8 @@ export default <Environment>({
       getVmContext() {
         return win
       },
-      teardown() {
-        win.happyDOM.cancelAsync()
+      async teardown() {
+        await win.happyDOM.cancelAsync()
       },
     }
   },
diff --git a/packages/vitest/src/integrations/env/jsdom.ts b/packages/vitest/src/integrations/env/jsdom.ts
index 30910b082f28..f6cc4dd14ef8 100644
--- a/packages/vitest/src/integrations/env/jsdom.ts
+++ b/packages/vitest/src/integrations/env/jsdom.ts
@@ -68,8 +68,6 @@ export default <Environment>({
 
     // TODO: browser doesn't expose Buffer, but a lot of dependencies use it
     dom.window.Buffer = Buffer
-    // Buffer extends Uint8Array
-    dom.window.Uint8Array = Uint8Array
 
     // inject structuredClone if it exists
     if (typeof structuredClone !== 'undefined' && !dom.window.structuredClone)