diff --git a/extensions/json/server/src/jsonParser.ts b/extensions/json/server/src/jsonParser.ts
index 230f7d5b816..810b7d51b0f 100644
--- a/extensions/json/server/src/jsonParser.ts
+++ b/extensions/json/server/src/jsonParser.ts
@@ -417,9 +417,9 @@ export class StringASTNode extends ASTNode {
 	public value: string;
 
 	constructor(parent: ASTNode, name: string, isKey: boolean, start: number, end?: number) {
+		super(parent, 'string', name, start, end);
 		this.isKey = isKey;
 		this.value = '';
-		super(parent, 'string', name, start, end);
 	}
 
 	public getValue(): any {