diff --git a/src/parsing/pattern-rewriter.cc b/src/parsing/pattern-rewriter.cc
index ba229ac08c..11d5d8ddc6 100644
--- a/src/parsing/pattern-rewriter.cc
+++ b/src/parsing/pattern-rewriter.cc
@@ -134,6 +134,7 @@ void Parser::DeclareAndInitializeVariables(
     Block* block, const DeclarationDescriptor* declaration_descriptor,
     const DeclarationParsingResult::Declaration* declaration,
     ZonePtrList<const AstRawString>* names) {
+  if (has_error()) return;
   PatternRewriter::DeclareAndInitializeVariables(
       this, block, declaration_descriptor, declaration, names);
 }
diff --git a/test/mjsunit/regress/regress-900585.js b/test/mjsunit/regress/regress-900585.js
new file mode 100644
index 0000000000..8969644f95
--- /dev/null
+++ b/test/mjsunit/regress/regress-900585.js
@@ -0,0 +1,5 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+assertThrows("/*for..in*/for(var [x5, functional] = this = function(id) { return id } in false) var x2, x;", ReferenceError);