diff --git a/tabby-terminal/src/frontends/xtermFrontend.ts b/tabby-terminal/src/frontends/xtermFrontend.ts
index f1e7785dc55c2ad4e51952aa94731801924d322f..4ce6eddd8bd43616978d5941c5f029d1d9af887d 100644
--- a/tabby-terminal/src/frontends/xtermFrontend.ts
+++ b/tabby-terminal/src/frontends/xtermFrontend.ts
@@ -186,6 +186,7 @@ export class XTermFrontend extends Frontend {
     detach (_host: HTMLElement): void {
         window.removeEventListener('resize', this.resizeHandler)
         this.resizeObserver?.disconnect()
+        delete this.resizeObserver
     }
 
     destroy (): void {