diff --git a/acorn/src/statement.js b/acorn/src/statement.js
index 632048449..23a903840 100644
--- a/acorn/src/statement.js
+++ b/acorn/src/statement.js
@@ -637,7 +637,7 @@ pp.parseClassMethod = function(method, isGenerator, isAsync, allowsDirectSuper)
 pp.parseClassId = function(node, isStatement) {
   if (this.type === tt.name) {
     node.id = this.parseIdent()
-    if (isStatement === true)
+    if (isStatement)
       this.checkLVal(node.id, BIND_LEXICAL, false)
   } else {
     if (isStatement === true)
diff --git a/test/tests-harmony.js b/test/tests-harmony.js
index 249a708b7..e37047489 100644
--- a/test/tests-harmony.js
+++ b/test/tests-harmony.js
@@ -4688,6 +4688,16 @@ testFail("export { encrypt }", "Export 'encrypt' is not defined (1:9)", {
   sourceType: "module"
 });
 
+testFail("class Test {}; export default class Test {}", "Identifier 'Test' has already been declared (1:36)", {
+  ecmaVersion: 6,
+  sourceType: "module"
+});
+
+test("export default class Test {}; export { Test }", {}, {
+  ecmaVersion: 6,
+  sourceType: "module"
+});
+
 testFail("export { encrypt, encrypt }", "Duplicate export 'encrypt' (1:18)", {
   ecmaVersion: 6,
   sourceType: "module"