diff --git a/jerry-core/parser/js/js-parser-statm.c b/jerry-core/parser/js/js-parser-statm.c
index 6a591b5f5..bdd2d1845 100644
--- a/jerry-core/parser/js/js-parser-statm.c
+++ b/jerry-core/parser/js/js-parser-statm.c
@@ -1168,6 +1168,11 @@ parser_parse_for_statement_start (parser_context_t *context_p) /**< context */
         || context_p->token.type == LEXER_KEYW_LET
         || context_p->token.type == LEXER_KEYW_CONST)
     {
+      if (context_p->status_flags & PARSER_IS_STRICT)
+      {
+        parser_raise_error (context_p, PARSER_ERR_FOR_IN_OF_DECLARATION);
+      }
+
       token_type = context_p->token.type;
       has_context = (context_p->token.type != LEXER_KEYW_VAR);
       scanner_get_location (&start_location, context_p);
diff --git a/jerry-core/parser/js/js-parser-util.c b/jerry-core/parser/js/js-parser-util.c
index 7b779c3e6..1601cb28d 100644
--- a/jerry-core/parser/js/js-parser-util.c
+++ b/jerry-core/parser/js/js-parser-util.c
@@ -951,6 +951,10 @@ parser_error_to_string (parser_error_t error) /**< error code */
     {
       return "Incorrect use of yield keyword.";
     }
+    case PARSER_ERR_FOR_IN_OF_DECLARATION:
+    {
+      return "for in-of loop variable declaration may not have an initializer.";
+    }
 #endif /* ENABLED (JERRY_ES2015) */
     case PARSER_ERR_DELETE_IDENT_NOT_ALLOWED:
     {
diff --git a/jerry-core/parser/js/js-parser.h b/jerry-core/parser/js/js-parser.h
index 1a09cb74a..e1e2588ab 100644
--- a/jerry-core/parser/js/js-parser.h
+++ b/jerry-core/parser/js/js-parser.h
@@ -80,6 +80,7 @@ typedef enum
 #if ENABLED (JERRY_ES2015)
   PARSER_ERR_USE_STRICT_NOT_ALLOWED,                  /**< use strict directive is not allowed */
   PARSER_ERR_YIELD_NOT_ALLOWED,                       /**< yield keyword is not allowed */
+  PARSER_ERR_FOR_IN_OF_DECLARATION,                   /**< variable declaration in for-in or for-of loop */
 #endif /* ENABLED (JERRY_ES2015) */
   PARSER_ERR_DELETE_IDENT_NOT_ALLOWED,                /**< identifier delete is not allowed in strict mode */
   PARSER_ERR_EVAL_CANNOT_ASSIGNED,                    /**< eval cannot be assigned in strict mode */
diff --git a/tests/jerry/es2015/forin-header-strict.js b/tests/jerry/es2015/forin-header-strict.js
new file mode 100644
index 000000000..07093c261
--- /dev/null
+++ b/tests/jerry/es2015/forin-header-strict.js
@@ -0,0 +1,29 @@
+/* Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+'use strict';
+try {
+  eval('for (var i = 0 in {}) {}');
+  assert(false);
+} catch(e) {
+  assert(e instanceof SyntaxError);
+}
+
+try {
+  eval('for (var = i of {}) {}');
+  assert(false);
+} catch (e) {
+  assert(e instanceof SyntaxError);
+}