diff --git a/lib/Parser.js b/lib/Parser.js
index 26f1916e527..11f72412d38 100644
--- a/lib/Parser.js
+++ b/lib/Parser.js
@@ -1005,6 +1005,7 @@ class Parser extends Tapable {
 			}
 		} else {
 			this.walkExpression(expression.right);
+			this.walkPattern(expression.left);
 			this.enterPattern(expression.left, (name, decl) => {
 				this.scope.renames["$" + name] = undefined;
 			});