diff --git a/src/vs/workbench/contrib/terminal/browser/terminalInstance.ts b/src/vs/workbench/contrib/terminal/browser/terminalInstance.ts
index 588c01f8628d2..b7c26c253a76d 100644
--- a/src/vs/workbench/contrib/terminal/browser/terminalInstance.ts
+++ b/src/vs/workbench/contrib/terminal/browser/terminalInstance.ts
@@ -1330,6 +1330,11 @@ export class TerminalInstance extends Disposable implements ITerminalInstance {
 			this._exitReason = reason ?? TerminalExitReason.Unknown;
 		}
 
+		// Dispose the resize debouncer before the process manager so that no
+		// resize callbacks can fire after ptyProcessReady has been nulled.
+		this._resizeDebouncer?.dispose();
+		this._resizeDebouncer = undefined;
+
 		this._processManager.dispose();
 		// Process manager dispose/shutdown doesn't fire process exit, trigger with undefined if it
 		// hasn't happened yet
diff --git a/src/vs/workbench/contrib/terminal/browser/terminalProcessManager.ts b/src/vs/workbench/contrib/terminal/browser/terminalProcessManager.ts
index 274c4b481e5b9..0c7cec8eca3c4 100644
--- a/src/vs/workbench/contrib/terminal/browser/terminalProcessManager.ts
+++ b/src/vs/workbench/contrib/terminal/browser/terminalProcessManager.ts
@@ -605,6 +605,9 @@ export class TerminalProcessManager extends Disposable implements ITerminalProce
 			return;
 		}
 
+		if (!this.ptyProcessReady) {
+			return Promise.resolve();
+		}
 		return this.ptyProcessReady.then(() => this._resize(cols, rows, pixelWidth, pixelHeight));
 	}