diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0e221b6d11..10de11c231 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,11 @@ _Note: Gaps between patch versions are faulty/broken releases._
 
 See [CHANGELOG - 6to5](CHANGELOG-6to5.md) for the pre-4.0.0 version changelog.
 
+## 5.1.8
+
+ * **Bug Fix**
+  * Only make parenthesized object pattern LHS illegal.
+
 ## 5.1.7
 
  * **Internal**
diff --git a/src/acorn/src/expression.js b/src/acorn/src/expression.js
index 8eaeab610f..cf8370c51c 100755
--- a/src/acorn/src/expression.js
+++ b/src/acorn/src/expression.js
@@ -103,12 +103,8 @@ pp.parseMaybeAssign = function(noIn, refShorthandDefaultPos, afterLeftParse) {
     node.left = this.type === tt.eq ? this.toAssignable(left) : left
     refShorthandDefaultPos.start = 0 // reset because shorthand default was used correctly
     this.checkLVal(left)
-    if (left.parenthesizedExpression) {
-      if (left.type === "ObjectPattern") {
-        this.raise(left.start, "You're trying to assign to a parenthesized expression, instead of `({ foo }) = {}` use `({ foo } = {})`");
-      } else {
-        this.raise(left.start, "Parenthesized left hand expressions are illegal");
-      }
+    if (left.parenthesizedExpression && left.type === "ObjectPattern") {
+      this.raise(left.start, "You're trying to assign to a parenthesized expression, instead of `({ foo }) = {}` use `({ foo } = {})`");
     }
     this.next()
     node.right = this.parseMaybeAssign(noIn)