diff --git a/src/libjsparser/parser.c b/src/libjsparser/parser.c
index b78197903..514b180a2 100644
--- a/src/libjsparser/parser.c
+++ b/src/libjsparser/parser.c
@@ -35,7 +35,7 @@ static void parse_statement (void);
 static T_IDX parse_assignment_expression (void);
 static void parse_source_element_list (void);
 
-static T_IDX temp_name, min_temp_name;
+static T_IDX temp_name, min_temp_name, strings_count;
 
 static T_IDX
 next_temp_name (void)
@@ -415,6 +415,14 @@ parse_argument_list (argument_list_type alt, T_IDX obj)
             case AL_CONSTRUCT_EXPR:
             case AL_CALL_EXPR:
               args[current_arg] = parse_assignment_expression ();
+              /* it's num literal.  */
+              if (strings_count < args[current_arg]
+                  && args[current_arg] < min_temp_name)
+                {
+                  T_IDX lhs = next_temp_name ();
+                  DUMP_OPCODE (assignment, OPCODE_ARG_TYPE_NUMBER, lhs, args[current_arg]);
+                  args[current_arg] = lhs;
+                }
               break;
 
             case AL_OBJECT_LIT:
@@ -1812,6 +1820,7 @@ void
 parser_init (void)
 {
   temp_name = min_temp_name = lexer_get_reserved_ids_count ();
+  strings_count = lexer_get_strings (NULL);
 #ifdef __HOST
   debug_file = __fopen ("parser.log", "w");
 #endif