diff --git a/.changeset/fluffy-doors-vanish.md b/.changeset/fluffy-doors-vanish.md
new file mode 100644
index 0000000000..ad458c0cc5
--- /dev/null
+++ b/.changeset/fluffy-doors-vanish.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fix TS errors when not using skipLibCheck
diff --git a/packages/astro/src/runtime/server/escape.ts b/packages/astro/src/runtime/server/escape.ts
index ebba8e1328..d6cd1de4a2 100644
--- a/packages/astro/src/runtime/server/escape.ts
+++ b/packages/astro/src/runtime/server/escape.ts
@@ -3,12 +3,15 @@ import { escape } from 'html-escaper';
 // Leverage the battle-tested `html-escaper` npm package.
 export const escapeHTML = escape;
 
-export class HTMLBytes extends Uint8Array {
-	// @ts-ignore
-	get [Symbol.toStringTag]() {
+export class HTMLBytes extends Uint8Array {}
+
+// TypeScript won't let us define this in the class body so have to do it
+// this way. Boo.
+Object.defineProperty(HTMLBytes.prototype, Symbol.toStringTag, {
+	get() {
 		return 'HTMLBytes';
 	}
-}
+});
 
 /**
  * A "blessed" extension of String that tells Astro that the string