diff --git a/.gitignore b/.gitignore
index fc3e1faa9..9f6957077 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,6 +25,7 @@ nbproject
 *.swp
 *~
 js.files
+js.fail.files
 jerry.error
 jerry.passed
 core
diff --git a/Makefile.mk b/Makefile.mk
index 6decebe58..383c8ae09 100644
--- a/Makefile.mk
+++ b/Makefile.mk
@@ -88,6 +88,9 @@ else
     OPTION_TODO := disable
 endif
 
+# Parser error code
+PARSER_ERROR_CODE := 255
+
 ifeq ($(fixme),1)
     OPTION_FIXME := enable
 else
@@ -514,6 +517,21 @@ $(CHECK_TARGETS):
             fi; \
             \
             exit $$status_code; \
+          fi; \
+          if [ -d $(TESTS_DIR)/fail/ ]; \
+          then \
+            VALGRIND=$(VALGRIND_CMD) TIMEOUT=$(VALGRIND_TIMEOUT) ./tools/jerry_test_fail.sh $(TARGET_DIR)/$(ENGINE_NAME) $(TARGET_DIR)/check $(PARSER_ERROR_CODE) $(TESTS_DIR) $(TESTS_OPTS) $$ADD_OPTS; \
+            status_code=$$?; \
+            if [ $$status_code -ne 0 ]; \
+            then \
+              echo $(TARGET) failed; \
+              if [ "$(OUTPUT_TO_LOG)" = "enable" ]; \
+              then \
+                echo See log in $(TARGET_DIR)/check directory for details.; \
+              fi; \
+              \
+              exit $$status_code; \
+            fi; \
           fi;
 
 
diff --git a/src/libjsparser/parser.c b/src/libjsparser/parser.c
index aeb665365..c2b44b379 100644
--- a/src/libjsparser/parser.c
+++ b/src/libjsparser/parser.c
@@ -878,22 +878,47 @@ cleanup:
   STACK_CHECK_USAGE (IDX);
 }
 
+static void
+emit_error_on_eval_and_arguments (idx_t id)
+{
+  if (id < lexer_get_strings_count ())
+  {
+    if (lp_string_equal_zt (lexer_get_string_by_id (id),
+                            ecma_get_magic_string_zt (ECMA_MAGIC_STRING_ARGUMENTS))
+        || lp_string_equal_zt (lexer_get_string_by_id (id),
+                               ecma_get_magic_string_zt (ECMA_MAGIC_STRING_EVAL)))
+    {
+      EMIT_ERROR ("'eval' and 'arguments' are not allowed here in strict mode");
+    }
+  }
+}
+
 static void
 check_for_eval_and_arguments_in_strict_mode (idx_t id)
 {
   if (parser_strict_mode ())
   {
-    if (id < lexer_get_strings_count ())
+    emit_error_on_eval_and_arguments (id);
+  }
+}
+
+static bool
+find_assignment_to (opcode_counter_t from, idx_t tmp_id, opcode_t *res)
+{
+  JERRY_ASSERT (res != NULL);
+  JERRY_ASSERT (tmp_id >= lexer_get_reserved_ids_count ());
+  for (opcode_counter_t oc = from; oc > 0; oc = (opcode_counter_t) (oc - 1))
+  {
+    *res = deserialize_opcode (oc);
+    if (OPCODE_IS ((*res), assignment))
     {
-      if (lp_string_equal_zt (lexer_get_string_by_id (id),
-                              ecma_get_magic_string_zt (ECMA_MAGIC_STRING_ARGUMENTS))
-          || lp_string_equal_zt (lexer_get_string_by_id (id),
-                                 ecma_get_magic_string_zt (ECMA_MAGIC_STRING_EVAL)))
+      if (res->data.assignment.var_left == tmp_id)
       {
-        EMIT_ERROR ("'eval' and 'arguments' are not allowed here in strict mode");
+        return true;
       }
     }
   }
+  return false;
 }
 
 static void
@@ -908,9 +933,9 @@ check_for_duplication_of_param (opcode_counter_t from, uint8_t metas_num)
   STACK_DECLARE_USAGE (U8);
   STACK_DECLARE_USAGE (ops);
 
+  STACK_PUSH (U8, 0); // seen metas
   STACK_PUSH (U8, STACK_SIZE (IDX));
 
-  uint8_t seen_metas = 0;
   for (opcode_counter_t oc = from; oc < OPCODE_COUNTER (); oc = (opcode_counter_t) (oc + 1))
   {
     STACK_PUSH (ops, deserialize_opcode (oc));
@@ -919,41 +944,58 @@ check_for_duplication_of_param (opcode_counter_t from, uint8_t metas_num)
       switch (STACK_TOP (ops).data.meta.type)
       {
         case OPCODE_META_TYPE_VARG:
-        case OPCODE_META_TYPE_VARG_PROP_DATA:
         {
           for (uint8_t i = STACK_TOP (U8); i < STACK_SIZE (IDX); i = (uint8_t) (i + 1))
           {
-            if (i == STACK_TOP (ops).data.meta.data_1)
+            if (STACK_ELEMENT (IDX, i) == STACK_TOP (ops).data.meta.data_1)
             {
-              JERRY_ASSERT (i < lexer_get_strings_count ());
-              EMIT_ERROR_VARG ("Duplication of identifier '%s' as parameter is not allowed in strict mode.",
-                               lexer_get_string_by_id (i));
+              JERRY_ASSERT (STACK_ELEMENT (IDX, i) < lexer_get_strings_count ());
+              EMIT_ERROR ("Duplication of identifier as parameter is not allowed in strict mode.");
             }
           }
-          /* FALLTHRU.  */
+          STACK_PUSH (IDX, STACK_TOP (ops).data.meta.data_1);
+          STACK_INCR_HEAD (U8, 2);
+          break;
+        }
+        case OPCODE_META_TYPE_VARG_PROP_DATA:
+        {
+          opcode_t res;
+          if (find_assignment_to (oc, STACK_TOP (ops).data.meta.data_1, &res))
+          {
+            for (uint8_t i = STACK_TOP (U8); i < STACK_SIZE (IDX); i = (uint8_t) (i + 1))
+            {
+              if (STACK_ELEMENT (IDX, i) == res.data.assignment.value_right)
+              {
+                JERRY_ASSERT (STACK_ELEMENT (IDX, i) < lexer_get_strings_count ());
+                EMIT_ERROR ("Duplication of identifier as parameter is not allowed in strict mode.");
+              }
+            }
+            STACK_PUSH (IDX, res.data.assignment.value_right);
+          }
+          /* FALLTHRU. */
         }
         case OPCODE_META_TYPE_THIS_ARG:
         case OPCODE_META_TYPE_VARG_PROP_GETTER:
         case OPCODE_META_TYPE_VARG_PROP_SETTER:
         {
-          seen_metas = (uint8_t) (seen_metas + 1);
+          STACK_INCR_HEAD (U8, 2);
           break;
         }
         default:
         {
-          JERRY_UNREACHABLE ();
+          break;
         }
       }
     }
     STACK_DROP (ops, 1);
-    if (seen_metas == metas_num)
+    if (STACK_HEAD (U8, 2) == metas_num)
     {
       break;
     }
   }
 
   STACK_DROP (IDX, STACK_SIZE (IDX) - STACK_TOP (U8));
-  STACK_DROP (U8, 1);
+  STACK_DROP (U8, 2);
 
   STACK_CHECK_USAGE (ops);
   STACK_CHECK_USAGE (U8);
@@ -1181,6 +1223,7 @@ next:
     }
     case AL_OBJ_DECL:
     {
+      check_for_duplication_of_param (STACK_TOP (U16), STACK_TOP (U8));
       REWRITE_OPCODE_2 (STACK_TOP (U16), obj_decl, ID(1), STACK_TOP (U8));
       break;
     }
@@ -1231,10 +1274,6 @@ parse_function_declaration (void)
   STACK_DECLARE_USAGE (scopes)
   STACK_DECLARE_USAGE (U8)
 
-  SET_OPCODE_COUNTER (0);
-  STACK_PUSH (scopes, scopes_tree_init (STACK_TOP (scopes)));
-  serializer_set_scope (STACK_TOP (scopes));
-
   assert_keyword (KW_FUNCTION);
 
   token_after_newlines_must_be (TOK_NAME);
@@ -1242,7 +1281,12 @@ parse_function_declaration (void)
   STACK_PUSH (IDX, token_data ());
 
   skip_newlines ();
+  SET_OPCODE_COUNTER (0);
+  STACK_PUSH (scopes, scopes_tree_init (STACK_TOP (scopes)));
+  serializer_set_scope (STACK_TOP (scopes));
+  scopes_tree_set_strict_mode (STACK_TOP (scopes), scopes_tree_strict_mode (STACK_HEAD (scopes, 2)));
   STACK_PUSH (U8, parse_argument_list (AL_FUNC_DECL, ID(1)));
+  scopes_tree_set_strict_mode (STACK_TOP (scopes), false);
 
   STACK_PUSH (U16, OPCODE_COUNTER ());
   DUMP_OPCODE_3 (meta, OPCODE_META_TYPE_UNDEFINED, INVALID_VALUE, INVALID_VALUE);
@@ -3778,16 +3822,16 @@ preparse_scope (bool is_global)
   STACK_PUSH (U8, is_global ? TOK_EOF : TOK_CLOSE_BRACE);
 
   STACK_PUSH (U16, OPCODE_COUNTER ());
-  DUMP_VOID_OPCODE (nop); /* use strict.  */
+
+  if (token_is (TOK_STRING) && lp_string_equal_s (lexer_get_string_by_id (token_data ()), "use strict"))
+  {
+    scopes_tree_set_strict_mode (STACK_TOP (scopes), true);
+    DUMP_OPCODE_3 (meta, OPCODE_META_TYPE_STRICT_CODE, INVALID_VALUE, INVALID_VALUE);
+  }
 
   while (!token_is (STACK_TOP (U8)))
   {
-    if (token_is (TOK_STRING) && lp_string_equal_s (lexer_get_string_by_id (token_data ()), "use strict"))
-    {
-      scopes_tree_set_strict_mode (STACK_TOP (scopes), true);
-      REWRITE_OPCODE_3 (STACK_TOP (U16), meta, OPCODE_META_TYPE_STRICT_CODE, INVALID_VALUE, INVALID_VALUE);
-    }
-    else if (is_keyword (KW_VAR))
+    if (is_keyword (KW_VAR))
     {
       preparse_var_decls ();
     }
diff --git a/tests/jerry/fail/255/arguments_assignment_strict.js b/tests/jerry/fail/255/arguments_assignment_strict.js
new file mode 100644
index 000000000..b581932d8
--- /dev/null
+++ b/tests/jerry/fail/255/arguments_assignment_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+arguments = 1;
diff --git a/tests/jerry/fail/255/arguments_catch_strict.js b/tests/jerry/fail/255/arguments_catch_strict.js
new file mode 100644
index 000000000..80b3fa1d4
--- /dev/null
+++ b/tests/jerry/fail/255/arguments_catch_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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{}catch(arguments){};
diff --git a/tests/jerry/fail/255/arguments_in_prop_set_param_list_strict.js b/tests/jerry/fail/255/arguments_in_prop_set_param_list_strict.js
new file mode 100644
index 000000000..ea4383bb4
--- /dev/null
+++ b/tests/jerry/fail/255/arguments_in_prop_set_param_list_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+var a = { set a(arguments) {} };
diff --git a/tests/jerry/fail/255/arguments_in_var_decl_strict.js b/tests/jerry/fail/255/arguments_in_var_decl_strict.js
new file mode 100644
index 000000000..7bd81940b
--- /dev/null
+++ b/tests/jerry/fail/255/arguments_in_var_decl_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+var arguments;
diff --git a/tests/jerry/fail/255/arguments_param_strict.js b/tests/jerry/fail/255/arguments_param_strict.js
new file mode 100644
index 000000000..6aecb72d0
--- /dev/null
+++ b/tests/jerry/fail/255/arguments_param_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+function f(arguments) {}
diff --git a/tests/jerry/fail/255/arguments_postfix_strict.js b/tests/jerry/fail/255/arguments_postfix_strict.js
new file mode 100644
index 000000000..bc319d524
--- /dev/null
+++ b/tests/jerry/fail/255/arguments_postfix_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+arguments++;
diff --git a/tests/jerry/fail/255/arguments_prefix_strict.js b/tests/jerry/fail/255/arguments_prefix_strict.js
new file mode 100644
index 000000000..217fa508e
--- /dev/null
+++ b/tests/jerry/fail/255/arguments_prefix_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+++arguments;
diff --git a/tests/jerry/fail/255/delete_strict.js b/tests/jerry/fail/255/delete_strict.js
new file mode 100644
index 000000000..fa82d732a
--- /dev/null
+++ b/tests/jerry/fail/255/delete_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+delete a;
diff --git a/tests/jerry/fail/255/eval_assignment_strict.js b/tests/jerry/fail/255/eval_assignment_strict.js
new file mode 100644
index 000000000..aa28ff6d4
--- /dev/null
+++ b/tests/jerry/fail/255/eval_assignment_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+eval = 1;
diff --git a/tests/jerry/fail/255/eval_catch_strict.js b/tests/jerry/fail/255/eval_catch_strict.js
new file mode 100644
index 000000000..c48f0a8f6
--- /dev/null
+++ b/tests/jerry/fail/255/eval_catch_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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{}catch(eval){};
diff --git a/tests/jerry/fail/255/eval_in_prop_set_param_list_strict.js b/tests/jerry/fail/255/eval_in_prop_set_param_list_strict.js
new file mode 100644
index 000000000..da21ecd8f
--- /dev/null
+++ b/tests/jerry/fail/255/eval_in_prop_set_param_list_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+var a = { set a(eval) {} };
diff --git a/tests/jerry/fail/255/eval_in_var_decl_strict.js b/tests/jerry/fail/255/eval_in_var_decl_strict.js
new file mode 100644
index 000000000..753197c5a
--- /dev/null
+++ b/tests/jerry/fail/255/eval_in_var_decl_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+var eval;
diff --git a/tests/jerry/fail/255/eval_param_strict.js b/tests/jerry/fail/255/eval_param_strict.js
new file mode 100644
index 000000000..689f4f58d
--- /dev/null
+++ b/tests/jerry/fail/255/eval_param_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+function f(eval) {}
diff --git a/tests/jerry/fail/255/eval_postfix_strict.js b/tests/jerry/fail/255/eval_postfix_strict.js
new file mode 100644
index 000000000..e908b5f71
--- /dev/null
+++ b/tests/jerry/fail/255/eval_postfix_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+eval++;
diff --git a/tests/jerry/fail/255/eval_prefix_strict.js b/tests/jerry/fail/255/eval_prefix_strict.js
new file mode 100644
index 000000000..55a0202e1
--- /dev/null
+++ b/tests/jerry/fail/255/eval_prefix_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+++eval;
diff --git a/tests/jerry/fail/255/let_strict.js b/tests/jerry/fail/255/let_strict.js
new file mode 100644
index 000000000..e39810412
--- /dev/null
+++ b/tests/jerry/fail/255/let_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+var let = 1;
diff --git a/tests/jerry/fail/255/object_several_prop_names_strict.js b/tests/jerry/fail/255/object_several_prop_names_strict.js
new file mode 100644
index 000000000..1426f3ef6
--- /dev/null
+++ b/tests/jerry/fail/255/object_several_prop_names_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+var a = {a:1, a:2};
diff --git a/tests/jerry/fail/255/octal_strict.js b/tests/jerry/fail/255/octal_strict.js
new file mode 100644
index 000000000..7e51a8129
--- /dev/null
+++ b/tests/jerry/fail/255/octal_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+var a = 07;
diff --git a/tests/jerry/fail/255/param_duplication_strict.js b/tests/jerry/fail/255/param_duplication_strict.js
new file mode 100644
index 000000000..ce645650d
--- /dev/null
+++ b/tests/jerry/fail/255/param_duplication_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+function f(a, a) {}
diff --git a/tests/jerry/fail/255/with_strict.js b/tests/jerry/fail/255/with_strict.js
new file mode 100644
index 000000000..34aa856d2
--- /dev/null
+++ b/tests/jerry/fail/255/with_strict.js
@@ -0,0 +1,17 @@
+// Copyright 2014 Samsung Electronics Co., Ltd.
+//
+// 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"
+
+with (Array) {}
diff --git a/tests/unit/test_preparser.c b/tests/unit/test_preparser.c
index c8f1a4d7c..658d27b8c 100644
--- a/tests/unit/test_preparser.c
+++ b/tests/unit/test_preparser.c
@@ -39,12 +39,11 @@ main( int __unused argc,
 
   if (!opcodes_equal(deserialize_bytecode (), (opcode_t[]) {
     [0] = getop_reg_var_decl (1, 2),    // var tmp1 .. tmp2;
-    [1] =          getop_nop (),        // ;
-    [2] =     getop_var_decl (0),       // var a;
-    [3] =   getop_assignment (1, 1, 1), // tmp1 = 1: SMALLINT;
-    [4] =   getop_assignment (0, 4, 1), // a = tmp1: TYPEOF(tmp1);
-    [5] =      getop_exitval (0)        // exit 0;
-  }, 6))
+    [1] =     getop_var_decl (0),       // var a;
+    [2] =   getop_assignment (1, 1, 1), // tmp1 = 1: SMALLINT;
+    [3] =   getop_assignment (0, 4, 1), // a = tmp1: TYPEOF(tmp1);
+    [4] =      getop_exitval (0)        // exit 0;
+  }, 5))
   {
     is_ok = false;
   }
diff --git a/tools/jerry_test_fail.sh b/tools/jerry_test_fail.sh
new file mode 100755
index 000000000..410c25fef
--- /dev/null
+++ b/tools/jerry_test_fail.sh
@@ -0,0 +1,138 @@
+# Copyright 2014 Samsung Electronics Co., Ltd.
+#
+# 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.
+
+#!/bin/bash
+
+TIMEOUT=${TIMEOUT:=5}
+
+START_DIR=`pwd`
+
+ENGINE=$START_DIR/$1
+shift
+
+OUT_DIR=$1
+shift
+
+ERROR_CODE=$1
+shift
+
+TESTS=$START_DIR/$1/fail/$ERROR_CODE
+shift
+
+ECHO_PROGRESS=1
+JERRY_ARGS=
+while (( "$#" ))
+do
+  if [ "$1" = "--parse-only" ]
+  then
+    JERRY_ARGS="$JERRY_ARGS $1"
+  fi
+  if [ "$1" = "--output-to-log" ]
+  then
+    exec 1>$OUT_DIR/jerry_test.log
+    ECHO_PROGRESS=0
+  fi
+  shift
+done
+
+if [ ! -x $ENGINE ]
+then
+  echo \"$ENGINE\" is not an executable file
+fi
+
+if [ ! -d $OUT_DIR ]
+then
+  mkdir -p $OUT_DIR
+fi
+cd $OUT_DIR
+
+JS_FILES=js.fail.files
+JERRY_ERROR=jerry.error
+JERRY_OK=jerry.passed
+
+rm -f $JS_FILES $JERRY_ERROR
+
+if [ -d $TESTS ];
+then
+ find $TESTS -name [^N]*.js -print | sort > $JS_FILES
+else
+ if [ -f $TESTS ];
+ then
+  cp $TESTS $JS_FILES
+ else
+  exit 1
+ fi;
+fi;
+total=$(cat $JS_FILES | wc -l)
+
+tested=0
+failed=0
+passed=0
+
+JERRY_TEMP=jerry.tmp
+
+exec 2>/dev/null
+
+echo "  Passed / Failed / Tested / Total / Percent"
+
+for test in `cat $JS_FILES`
+do
+    percent=$(echo $tested*100/$total | bc)
+
+    ( ulimit -t $TIMEOUT; $VALGRIND ${ENGINE} ${test} ${JERRY_ARGS} >&$JERRY_TEMP; exit $? );
+    status_code=$?
+
+    if [ $ECHO_PROGRESS -eq 1 ]
+    then
+      printf "\r\e[2K[ %6d / %6d / %6d / %5d / %3d%%    ]" ${passed} ${failed} ${tested} ${total} ${percent}
+    fi
+
+    if [ $status_code -ne $ERROR_CODE ]
+    then
+        echo "$status_code: ${test}" >> $JERRY_ERROR
+        echo "============================================" >> $JERRY_ERROR
+        cat $JERRY_TEMP >> $JERRY_ERROR
+        echo "============================================" >> $JERRY_ERROR
+        echo >> $JERRY_ERROR
+        echo >> $JERRY_ERROR
+
+        failed=$((failed+1))
+    else
+        echo "${test}" >> $JERRY_OK
+        passed=$((passed+1))
+    fi
+
+    tested=$((tested+1))
+done
+
+rm $JERRY_TEMP
+
+printf "\r\e[2K[ %6d / %6d / %6d / %5d / %3d%%    ]\n" ${passed} ${failed} ${tested} ${total} ${percent}
+
+ratio=$(echo $passed*100/$total | bc)
+
+echo ==========================
+echo "Number of tests passed:   ${passed}"
+echo "Number of tests failed:   ${failed}"
+echo --------------------------
+echo "Total number of tests:    ${total}"
+echo "Passed:                   ${ratio}%"
+
+if [ ${failed} -ne 0 ]
+then
+   echo "See $JERRY_ERROR for details about failures"
+   exit 1;
+fi
+
+exit 0