diff --git a/extensions/typescript/src/utils/managedFileContext.ts b/extensions/typescript/src/utils/managedFileContext.ts
index a4aeca7dfae69c00c0c67d28267ec0983e523fac..c8755aa4db780e0b41fb6501181148839eae68e9 100644
--- a/extensions/typescript/src/utils/managedFileContext.ts
+++ b/extensions/typescript/src/utils/managedFileContext.ts
@@ -31,9 +31,11 @@ export default class ManagedFileContextManager {
 		this.onDidChangeActiveTextEditorSub.dispose();
 	}
 
-	private onDidChangeActiveTextEditor(editor: vscode.TextEditor): any {
-		const isManagedFile = isSupportedLanguageMode(editor.document) && this.normalizePath(editor.document.uri) !== null;
-		this.updateContext(isManagedFile);
+	private onDidChangeActiveTextEditor(editor?: vscode.TextEditor): any {
+		if (editor) {
+			const isManagedFile = isSupportedLanguageMode(editor.document) && this.normalizePath(editor.document.uri) !== null;
+			this.updateContext(isManagedFile);
+		}
 	}
 
 	private updateContext(newValue: boolean) {