Index: Zend/zend_language_scanner.l
===================================================================
--- Zend/zend_language_scanner.l	(révision 25)
+++ Zend/zend_language_scanner.l	(révision 33)
@@ -870,6 +870,10 @@
 	return T_CONST;
 }
 
+<ST_IN_SCRIPTING>"enum" {
+    return T_ENUM;
+}
+
 <ST_IN_SCRIPTING>"return" {
 	return T_RETURN;
 }
Index: Zend/zend_language_parser.y
===================================================================
--- Zend/zend_language_parser.y	(révision 25)
+++ Zend/zend_language_parser.y	(révision 33)
@@ -156,6 +156,7 @@
 %token T_NS_C
 %token T_DIR
 %token T_NS_SEPARATOR
+%token T_ENUM
 
 %% /* Rules */
 
@@ -200,10 +201,20 @@
 ;
 
 constant_declaration:
-		constant_declaration ',' T_STRING '=' static_scalar	{ zend_do_declare_constant(&$3, &$5 TSRMLS_CC); }
-	|	T_CONST T_STRING '=' static_scalar { zend_do_declare_constant(&$2, &$4 TSRMLS_CC); }
+		constant_declaration ',' inner_constant_declaration
+	|	T_CONST inner_constant_declaration
 ;
 
+inner_constant_declaration:
+		T_STRING '=' static_scalar { zend_do_declare_constant(&$1, &$3 TSRMLS_CC); }
+	|	T_ENUM { CG(enum_current_value) = 0; } '{' constant_enum_declaration '}'
+;
+
+constant_enum_declaration:
+		constant_enum_declaration ',' T_STRING constant_enum_value { zend_do_declare_constant(&$3, &$4 TSRMLS_CC); }
+	|	T_STRING constant_enum_value { zend_do_declare_constant(&$1, &$2 TSRMLS_CC); }
+;
+
 inner_statement_list:
 		inner_statement_list  { zend_do_extended_info(TSRMLS_C); } inner_statement { HANDLE_INTERACTIVE(); }
 	|	/* empty */
@@ -628,10 +639,25 @@
 ;
 
 class_constant_declaration:
-		class_constant_declaration ',' T_STRING '=' static_scalar	{ zend_do_declare_class_constant(&$3, &$5 TSRMLS_CC); }
-	|	T_CONST T_STRING '=' static_scalar	{ zend_do_declare_class_constant(&$2, &$4 TSRMLS_CC); }
+		class_constant_declaration ',' class_constant_inner_declaration 
+	|	T_CONST class_constant_inner_declaration
 ;
 
+class_constant_inner_declaration:
+		T_STRING '=' static_scalar { zend_do_declare_class_constant(&$1, &$3 TSRMLS_CC); }
+	|	T_ENUM { CG(enum_current_value) = 0; } '{' class_constant_enum_declaration '}'
+;
+
+class_constant_enum_declaration:
+		class_constant_enum_declaration ',' T_STRING constant_enum_value { zend_do_declare_class_constant(&$3, &$4 TSRMLS_CC); }
+	|	T_STRING constant_enum_value { zend_do_declare_class_constant(&$1, &$2 TSRMLS_CC); }
+; 
+
+constant_enum_value:
+		'=' T_LNUMBER { $$ = $2; CG(enum_current_value) = Z_LVAL($$.u.constant); }
+	|	/* empty */ { $$.op_type = IS_CONST; INIT_PZVAL(&$$.u.constant); Z_TYPE($$.u.constant) = IS_LONG;  Z_LVAL($$.u.constant) = ++CG(enum_current_value); }
+;
+
 echo_expr_list:
 		echo_expr_list ',' expr { zend_do_echo(&$3 TSRMLS_CC); }
 	|	expr					{ zend_do_echo(&$1 TSRMLS_CC); }
Index: Zend/zend_globals.h
===================================================================
--- Zend/zend_globals.h	(révision 25)
+++ Zend/zend_globals.h	(révision 33)
@@ -151,6 +151,7 @@
 	void (*interned_strings_snapshot)(TSRMLS_D);
 	void (*interned_strings_restore)(TSRMLS_D);
 
+	long enum_current_value;
 #ifdef ZEND_MULTIBYTE
 	zend_encoding **script_encoding_list;
 	size_t script_encoding_list_size;