diff --git a/src/vs/workbench/contrib/terminal/browser/terminalInstance.ts b/src/vs/workbench/contrib/terminal/browser/terminalInstance.ts
index 6b744c7b073a62194b376969fbc53cbc2d5238dc..e7e23ed4ff0851ecbf290d244e44c7a9fa1dc398 100644
--- a/src/vs/workbench/contrib/terminal/browser/terminalInstance.ts
+++ b/src/vs/workbench/contrib/terminal/browser/terminalInstance.ts
@@ -762,7 +762,11 @@ export class TerminalInstance implements ITerminalInstance {
 		if (!this._xterm) {
 			return;
 		}
-		const text = window.getSelection().toString();
+		const selection = window.getSelection();
+		if (!selection) {
+			return;
+		}
+		const text = selection.toString();
 		if (!text || force) {
 			this._xterm.focus();
 		}