diff --git a/src/libcoreint/opcodes-ecma-arithmetics.c b/src/libcoreint/opcodes-ecma-arithmetics.c
index 1f24e61c0..3db3857a5 100644
--- a/src/libcoreint/opcodes-ecma-arithmetics.c
+++ b/src/libcoreint/opcodes-ecma-arithmetics.c
@@ -128,7 +128,20 @@ opfunc_addition (opcode_t opdata, /**< operation data */
   if (prim_left_value.value.value_type == ECMA_TYPE_STRING
       || prim_right_value.value.value_type == ECMA_TYPE_STRING)
   {
-    JERRY_UNIMPLEMENTED ();
+    ECMA_TRY_CATCH (str_left_value, ecma_op_to_string (prim_left_value.value), ret_value);
+    ECMA_TRY_CATCH (str_right_value, ecma_op_to_string (prim_right_value.value), ret_value);
+
+    ecma_string_t *string1_p = ECMA_GET_POINTER (str_left_value.value.value);
+    ecma_string_t *string2_p = ECMA_GET_POINTER (str_right_value.value.value);
+
+    ecma_string_t *concat_str_p = ecma_concat_ecma_strings (string1_p, string2_p);
+
+    ret_value = set_variable_value (int_data, dst_var_idx, ecma_make_string_value (concat_str_p));
+
+    ecma_deref_ecma_string (concat_str_p);
+
+    ECMA_FINALIZE (str_right_value);
+    ECMA_FINALIZE (str_left_value);
   }
   else
   {
diff --git a/tests/jerry/string.js b/tests/jerry/string.js
new file mode 100644
index 000000000..2467e7d94
--- /dev/null
+++ b/tests/jerry/string.js
@@ -0,0 +1,18 @@
+// 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.
+
+var a = 'abcd';
+var b = 'dfgh';
+
+c = a + b;