diff --git a/memcached-api.php b/memcached-api.php
index ecc4072c..45641415 100644
--- a/memcached-api.php
+++ b/memcached-api.php
@@ -185,13 +185,13 @@ class Memcached {
 
 	public function __construct( $persistent_id = '', $on_new_object_cb = null ) {}
 	
-	public function get( $key, $cache_cb = null, &$cas_token = null ) {}
+	public function get( $key, $cache_cb = null, &$cas_token = null, &$udf_flags = null ) {}
 
-	public function getByKey( $server_key, $key, $cache_cb = null, &$cas_token = null ) {}
+	public function getByKey( $server_key, $key, $cache_cb = null, &$cas_token = null, &$udf_flags = null ) {}
 
-	public function getMulti( array $keys, &$cas_tokens = null, $flags = 0 ) {}
+	public function getMulti( array $keys, &$cas_tokens = null, $flags = 0, &$udf_flags = null ) {}
 
-	public function getMultiByKey( $server_key, array $keys, &$cas_tokens = null, $flags = 0 ) {}
+	public function getMultiByKey( $server_key, array $keys, &$cas_tokens = null, $flags = 0, &$udf_flags = null ) {}
 
 	public function getDelayed( array $keys, $with_cas = null, $value_cb = null ) {}
 
@@ -201,25 +201,25 @@ public function fetch( ) {}
 	
 	public function fetchAll( ) {}
 
-	public function set( $key, $value, $expiration = 0 ) {}
+	public function set( $key, $value, $expiration = 0, $udf_flags = 0 ) {}
 
     public function touch( $key, $expiration = 0 ) {}
 
     public function touchbyKey( $key, $expiration = 0 ) {}
 
-	public function setByKey( $server_key, $key, $value, $expiration = 0 ) {}
+	public function setByKey( $server_key, $key, $value, $expiration = 0, $udf_flags = 0 ) {}
 
-	public function setMulti( array $items, $expiration = 0 ) {}
+	public function setMulti( array $items, $expiration = 0, $udf_flags = 0 ) {}
 
-	public function setMultiByKey( $server_key, array $items, $expiration = 0 ) {}
+	public function setMultiByKey( $server_key, array $items, $expiration = 0, $udf_flags = 0 ) {}
 
-	public function cas( $token, $key, $value, $expiration = 0 ) {}
+	public function cas( $token, $key, $value, $expiration = 0, $udf_flags = 0 ) {}
 
-	public function casByKey( $token, $server_key, $key, $value, $expiration = 0 ) {}
+	public function casByKey( $token, $server_key, $key, $value, $expiration = 0, $udf_flags = 0 ) {}
 
-	public function add( $key, $value, $expiration = 0 ) {}
+	public function add( $key, $value, $expiration = 0, $udf_flags = 0 ) {}
 
-	public function addByKey( $server_key, $key, $value, $expiration = 0 ) {}
+	public function addByKey( $server_key, $key, $value, $expiration = 0, $udf_flags = 0 ) {}
 
 	public function append( $key, $value ) {}
 
@@ -229,9 +229,9 @@ public function prepend( $key, $value ) {}
 
 	public function prependByKey( $server_key, $key, $value ) {}
 
-	public function replace( $key, $value, $expiration = 0 ) {}
+	public function replace( $key, $value, $expiration = 0, $udf_flags = 0 ) {}
 
-	public function replaceByKey( $server_key, $key, $value, $expiration = 0 ) {}
+	public function replaceByKey( $server_key, $key, $value, $expiration = 0, $udf_flags = 0 ) {}
 
 	public function delete( $key, $time = 0 ) {}
 
diff --git a/php_memcached.c b/php_memcached.c
index 4074e591..c3f1874b 100644
--- a/php_memcached.c
+++ b/php_memcached.c
@@ -136,6 +136,13 @@ typedef unsigned long int uint32_t;
 #define MEMC_VAL_COMPRESSION_ZLIB    (1<<5)
 #define MEMC_VAL_COMPRESSION_FASTLZ  (1<<6)
 
+/****************************************
+  User-defined flags
+****************************************/
+#define MEMC_UDF_MASK     0xff00
+#define MEMC_UDF_GET(flags)              ((long)(flags & MEMC_UDF_MASK)>>8)
+#define MEMC_UDF_SET(flags, udf_flags)   ((flags) |= ((udf_flags<<8) & MEMC_UDF_MASK))
+
 /****************************************
   "get" operation flags
 ****************************************/
@@ -507,7 +514,7 @@ static PHP_METHOD(Memcached, __construct)
 }
 /* }}} */
 
-/* {{{ Memcached::get(string key [, mixed callback [, double &cas_token ] ])
+/* {{{ Memcached::get(string key [, mixed callback [, double &cas_token [, int &udf_flags ] ] ])
    Returns a value for the given key or false */
 PHP_METHOD(Memcached, get)
 {
@@ -515,7 +522,7 @@ PHP_METHOD(Memcached, get)
 }
 /* }}} */
 
-/* {{{ Memcached::getByKey(string server_key, string key [, mixed callback [, double &cas_token ] ])
+/* {{{ Memcached::getByKey(string server_key, string key [, mixed callback [, double &cas_token [, int &udf_flags ] ] ])
    Returns a value for key from the server identified by the server key or false */
 PHP_METHOD(Memcached, getByKey)
 {
@@ -537,6 +544,7 @@ static void php_memc_get_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
 	const char* keys[1] = { NULL };
 	size_t key_lens[1] = { 0 };
 	zval *cas_token = NULL;
+	zval *udf_flags = NULL;
 	zend_fcall_info fci = empty_fcall_info;
 	zend_fcall_info_cache fcc = empty_fcall_info_cache;
 	memcached_result_st result;
@@ -544,13 +552,13 @@ static void php_memc_get_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
 	MEMC_METHOD_INIT_VARS;
 
 	if (by_key) {
-		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "ss|f!z", &server_key,
-								  &server_key_len, &key, &key_len, &fci, &fcc, &cas_token) == FAILURE) {
+		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "ss|f!zz", &server_key,
+								  &server_key_len, &key, &key_len, &fci, &fcc, &cas_token, &udf_flags) == FAILURE) {
 			return;
 		}
 	} else {
-		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|f!z", &key, &key_len,
-								  &fci, &fcc, &cas_token) == FAILURE) {
+		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|f!zz", &key, &key_len,
+								  &fci, &fcc, &cas_token, &udf_flags) == FAILURE) {
 			return;
 		}
 	}
@@ -572,13 +580,13 @@ static void php_memc_get_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
 	/*
 		* Enable CAS support, but only if it is currently disabled.
 		*/
-	if (cas_token && orig_cas_flag == 0) {
+	if (cas_token && PZVAL_IS_REF(cas_token) && orig_cas_flag == 0) {
 		memcached_behavior_set(m_obj->memc, MEMCACHED_BEHAVIOR_SUPPORT_CAS, 1);
 	}
 
 	status = memcached_mget_by_key(m_obj->memc, server_key, server_key_len, keys, key_lens, 1);
 
-	if (cas_token && orig_cas_flag == 0) {
+	if (cas_token && PZVAL_IS_REF(cas_token) && orig_cas_flag == 0) {
 		memcached_behavior_set(m_obj->memc, MEMCACHED_BEHAVIOR_SUPPORT_CAS, orig_cas_flag);
 	}
 
@@ -642,11 +650,16 @@ static void php_memc_get_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
 		ZVAL_DOUBLE(cas_token, (double)cas);
 	}
 
+	if (udf_flags) {
+		zval_dtor(udf_flags);
+		ZVAL_LONG(udf_flags, MEMC_UDF_GET(flags));
+	}
+
 	memcached_result_free(&result);
 }
 /* }}} */
 
-/* {{{ Memcached::getMulti(array keys [, array &cas_tokens ])
+/* {{{ Memcached::getMulti(array keys [, array &cas_tokens [, array &udf_flags ] ])
    Returns values for the given keys or false */
 PHP_METHOD(Memcached, getMulti)
 {
@@ -654,7 +667,7 @@ PHP_METHOD(Memcached, getMulti)
 }
 /* }}} */
 
-/* {{{ Memcached::getMultiByKey(string server_key, array keys [, array &cas_tokens ])
+/* {{{ Memcached::getMultiByKey(string server_key, array keys [, array &cas_tokens [, array &udf_flags ] ])
    Returns values for the given keys from the server identified by the server key or false */
 PHP_METHOD(Memcached, getMultiByKey)
 {
@@ -679,6 +692,7 @@ static void php_memc_getMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_ke
 	uint32_t flags;
 	uint64_t cas = 0;
 	zval *cas_tokens = NULL;
+	zval *udf_flags = NULL;
 	uint64_t orig_cas_flag;
 	zval *value;
 	long get_flags = 0;
@@ -689,12 +703,12 @@ static void php_memc_getMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_ke
 	MEMC_METHOD_INIT_VARS;
 
 	if (by_key) {
-		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "sa/|zl", &server_key,
-								  &server_key_len, &keys, &cas_tokens, &get_flags) == FAILURE) {
+		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "sa/|zlz", &server_key,
+								  &server_key_len, &keys, &cas_tokens, &get_flags, &udf_flags) == FAILURE) {
 			return;
 		}
 	} else {
-		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "a/|zl", &keys, &cas_tokens, &get_flags) == FAILURE) {
+		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "a/|zlz", &keys, &cas_tokens, &get_flags, &udf_flags) == FAILURE) {
 			return;
 		}
 	}
@@ -741,7 +755,7 @@ static void php_memc_getMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_ke
 	/*
 	 * Enable CAS support, but only if it is currently disabled.
 	 */
-	if (cas_tokens) {
+	if (cas_tokens && PZVAL_IS_REF(cas_tokens)) {
 		orig_cas_flag = memcached_behavior_get(m_obj->memc, MEMCACHED_BEHAVIOR_SUPPORT_CAS);
 		if (orig_cas_flag == 0) {
 			memcached_behavior_set(m_obj->memc, MEMCACHED_BEHAVIOR_SUPPORT_CAS, 1);
@@ -755,7 +769,7 @@ static void php_memc_getMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_ke
 	/*
 	 * Restore the CAS support flag, but only if we had to turn it on.
 	 */
-	if (cas_tokens && orig_cas_flag == 0) {
+	if (cas_tokens && PZVAL_IS_REF(cas_tokens) && orig_cas_flag == 0) {
 		memcached_behavior_set(m_obj->memc, MEMCACHED_BEHAVIOR_SUPPORT_CAS, orig_cas_flag);
 	}
 
@@ -767,8 +781,26 @@ static void php_memc_getMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_ke
 	 * returned as doubles, because we cannot store potential 64-bit values in longs.
 	 */
 	if (cas_tokens) {
-		zval_dtor(cas_tokens);
-		array_init(cas_tokens);
+		if (PZVAL_IS_REF(cas_tokens)) {
+			// cas_tokens was passed by reference, we'll create an array for it.
+			zval_dtor(cas_tokens);
+			array_init(cas_tokens);
+		} else {
+			// Not pased by reference, we allow this (eg.: if you specify null
+			// to not enable cas but you want to use the udf_flags parameter).
+			// We destruct it and set it to null for the peace of mind.
+			zval_dtor(cas_tokens);
+			cas_tokens = NULL;
+		}
+	}
+
+	/*
+	 * Iterate through the result set and create the result array. The flags are
+	 * returned as longs.
+	 */
+	if (udf_flags) {
+		zval_dtor(udf_flags);
+		array_init(udf_flags);
 	}
 
 	memcached_result_create(m_obj->memc, &result);
@@ -816,6 +848,9 @@ static void php_memc_getMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_ke
 			cas = memcached_result_cas(&result);
 			add_assoc_double_ex(cas_tokens, res_key, res_key_len+1, (double)cas);
 		}
+		if (udf_flags) {
+			add_assoc_long_ex(udf_flags, res_key, res_key_len+1, MEMC_UDF_GET(flags));
+		}
 	}
 
 	memcached_result_free(&result);
@@ -826,6 +861,10 @@ static void php_memc_getMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_ke
 			zval_dtor(cas_tokens);
 			ZVAL_NULL(cas_tokens);
 		}
+		if (udf_flags) {
+			zval_dtor(udf_flags);
+			ZVAL_NULL(udf_flags);
+		}
 		zval_dtor(return_value);
 		RETURN_FALSE;
 	}
@@ -1022,6 +1061,9 @@ PHP_METHOD(Memcached, fetch)
 		/* XXX: also check against ULLONG_MAX or memc_behavior */
 		add_assoc_double_ex(return_value, ZEND_STRS("cas"), (double)cas);
 	}
+	if ((flags & MEMC_UDF_MASK) != 0) {
+		add_assoc_long_ex(return_value, ZEND_STRS("flags"), MEMC_UDF_GET(flags));
+	}
 
 	memcached_result_free(&result);
 }
@@ -1078,6 +1120,9 @@ PHP_METHOD(Memcached, fetchAll)
 			/* XXX: also check against ULLONG_MAX or memc_behavior */
 			add_assoc_double_ex(entry, ZEND_STRS("cas"), (double)cas);
 		}
+		if ((flags & MEMC_UDF_MASK) != 0) {
+			add_assoc_long_ex(entry, ZEND_STRS("flags"), MEMC_UDF_GET(flags));
+		}
 		add_next_index_zval(return_value, entry);
 	}
 
@@ -1090,7 +1135,7 @@ PHP_METHOD(Memcached, fetchAll)
 }
 /* }}} */
 
-/* {{{ Memcached::set(string key, mixed value [, int expiration ])
+/* {{{ Memcached::set(string key, mixed value [, int expiration [, int udf_flags ] ])
    Sets the value for the given key */
 PHP_METHOD(Memcached, set)
 {
@@ -1098,7 +1143,7 @@ PHP_METHOD(Memcached, set)
 }
 /* }}} */
 
-/* {{{ Memcached::setByKey(string server_key, string key, mixed value [, int expiration ])
+/* {{{ Memcached::setByKey(string server_key, string key, mixed value [, int expiration [, int udf_flags ] ])
    Sets the value for the given key on the server identified by the server key */
 PHP_METHOD(Memcached, setByKey)
 {
@@ -1125,7 +1170,7 @@ PHP_METHOD(Memcached, touchByKey)
 #endif
 
 
-/* {{{ Memcached::setMulti(array items [, int expiration ])
+/* {{{ Memcached::setMulti(array items [, int expiration [, int udf_flags ] ])
    Sets the keys/values specified in the items array */
 PHP_METHOD(Memcached, setMulti)
 {
@@ -1133,7 +1178,7 @@ PHP_METHOD(Memcached, setMulti)
 }
 /* }}} */
 
-/* {{{ Memcached::setMultiByKey(string server_key, array items [, int expiration ])
+/* {{{ Memcached::setMultiByKey(string server_key, array items [, int expiration [, int udf_flags ] ])
    Sets the keys/values specified in the items array on the server identified by the given server key */
 PHP_METHOD(Memcached, setMultiByKey)
 {
@@ -1173,6 +1218,7 @@ static void php_memc_setMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_ke
 	char *server_key = NULL;
 	int   server_key_len = 0;
 	time_t expiration = 0;
+	uint32_t udf_flags = 0;
 	zval **entry;
 	char *str_key;
 	uint  str_key_len;
@@ -1186,12 +1232,12 @@ static void php_memc_setMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_ke
 	MEMC_METHOD_INIT_VARS;
 
 	if (by_key) {
-		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "sa|l", &server_key,
-								  &server_key_len, &entries, &expiration) == FAILURE) {
+		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "sa|ll", &server_key,
+								  &server_key_len, &entries, &expiration, &udf_flags) == FAILURE) {
 			return;
 		}
 	} else {
-		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "a|l", &entries, &expiration) == FAILURE) {
+		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "a|ll", &entries, &expiration, &udf_flags) == FAILURE) {
 			return;
 		}
 	}
@@ -1199,6 +1245,16 @@ static void php_memc_setMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_ke
 	MEMC_METHOD_FETCH_OBJECT;
 	i_obj->rescode = MEMCACHED_SUCCESS;
 
+	/*
+	 * php_memcached uses 8 bits internally to store type, compression and serialization info.
+	 * We use 8 upper bits to store user defined flags.
+	 */
+	if (udf_flags > 0) {
+		if (udf_flags > (MEMC_UDF_MASK>>8)) {
+			php_error_docref(NULL TSRMLS_CC, E_WARNING, "udf_flags will be limited to %d", (MEMC_UDF_MASK>>8));
+		}
+	}
+
 	for (zend_hash_internal_pointer_reset(Z_ARRVAL_P(entries));
 		zend_hash_get_current_data(Z_ARRVAL_P(entries), (void**)&entry) == SUCCESS;
 		zend_hash_move_forward(Z_ARRVAL_P(entries))) {
@@ -1221,6 +1277,10 @@ static void php_memc_setMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_ke
 			flags |= MEMC_VAL_COMPRESSED;
 		}
 
+		if (udf_flags > 0) {
+			MEMC_UDF_SET(flags, udf_flags);
+		}
+
 		payload = php_memc_zval_to_payload(*entry, &payload_len, &flags, m_obj->serializer, m_obj->compression_type TSRMLS_CC);
 		if (payload == NULL) {
 			i_obj->rescode = MEMC_RES_PAYLOAD_FAILURE;
@@ -1246,7 +1306,7 @@ static void php_memc_setMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_ke
 }
 /* }}} */
 
-/* {{{ Memcached::add(string key, mixed value [, int expiration ])
+/* {{{ Memcached::add(string key, mixed value [, int expiration [, int udf_flags ] ])
    Sets the value for the given key, failing if the key already exists */
 PHP_METHOD(Memcached, add)
 {
@@ -1254,7 +1314,7 @@ PHP_METHOD(Memcached, add)
 }
 /* }}} */
 
-/* {{{ Memcached::addByKey(string server_key, string key, mixed value [, int expiration ])
+/* {{{ Memcached::addByKey(string server_key, string key, mixed value [, int expiration [, int udf_flags ] ])
    Sets the value for the given key on the server identified by the sever key, failing if the key already exists */
 PHP_METHOD(Memcached, addByKey)
 {
@@ -1294,7 +1354,7 @@ PHP_METHOD(Memcached, prependByKey)
 }
 /* }}} */
 
-/* {{{ Memcached::replace(string key, mixed value [, int expiration ])
+/* {{{ Memcached::replace(string key, mixed value [, int expiration [, int udf_flags ] ])
    Replaces the value for the given key, failing if the key doesn't exist */
 PHP_METHOD(Memcached, replace)
 {
@@ -1302,7 +1362,7 @@ PHP_METHOD(Memcached, replace)
 }
 /* }}} */
 
-/* {{{ Memcached::replaceByKey(string server_key, string key, mixed value [, int expiration ])
+/* {{{ Memcached::replaceByKey(string server_key, string key, mixed value [, int expiration [, int udf_flags ] ])
    Replaces the value for the given key on the server identified by the server key, failing if the key doesn't exist */
 PHP_METHOD(Memcached, replaceByKey)
 {
@@ -1323,6 +1383,7 @@ static void php_memc_store_impl(INTERNAL_FUNCTION_PARAMETERS, int op, zend_bool
 	zval  s_zvalue;
 	zval *value;
 	long expiration = 0;
+	uint32_t udf_flags = 0;
 	char  *payload;
 	size_t payload_len;
 	uint32_t flags = 0;
@@ -1345,8 +1406,8 @@ static void php_memc_store_impl(INTERNAL_FUNCTION_PARAMETERS, int op, zend_bool
 				return;
 			}
 		} else {
-			if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "ssz|l", &server_key,
-									  &server_key_len, &key, &key_len, &value, &expiration) == FAILURE) {
+			if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "ssz|ll", &server_key,
+									  &server_key_len, &key, &key_len, &value, &expiration, &udf_flags) == FAILURE) {
 				return;
 			}
 		}
@@ -1365,8 +1426,8 @@ static void php_memc_store_impl(INTERNAL_FUNCTION_PARAMETERS, int op, zend_bool
 				return;
 			}
 		} else {
-			if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "sz|l", &key, &key_len,
-									  &value, &expiration) == FAILURE) {
+			if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "sz|ll", &key, &key_len,
+									  &value, &expiration, &udf_flags) == FAILURE) {
 				return;
 			}
 		}
@@ -1393,6 +1454,18 @@ static void php_memc_store_impl(INTERNAL_FUNCTION_PARAMETERS, int op, zend_bool
 		flags |= MEMC_VAL_COMPRESSED;
 	}
 
+	/*
+	 * php_memcached uses 8 bits internally to store type, compression and serialization info.
+	 * We use 8 upper bits to store user defined flags.
+	 */
+	if (udf_flags > 0) {
+		if (udf_flags > (MEMC_UDF_MASK>>8)) {
+			php_error_docref(NULL TSRMLS_CC, E_WARNING, "udf_flags will be limited to %d", (MEMC_UDF_MASK>>8));
+		}
+
+		MEMC_UDF_SET(flags, udf_flags);
+	}
+
 	if (op == MEMC_OP_TOUCH) {
 #if defined(LIBMEMCACHED_VERSION_HEX) && LIBMEMCACHED_VERSION_HEX < 0x01000016
 		if (memcached_behavior_get(m_obj->memc, MEMCACHED_BEHAVIOR_BINARY_PROTOCOL)) {
@@ -1492,6 +1565,7 @@ static void php_memc_cas_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
 	int   server_key_len = 0;
 	zval *value;
 	time_t expiration = 0;
+	uint32_t udf_flags = 0;
 	char  *payload;
 	size_t payload_len;
 	uint32_t flags = 0;
@@ -1499,13 +1573,13 @@ static void php_memc_cas_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
 	MEMC_METHOD_INIT_VARS;
 
 	if (by_key) {
-		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "dssz|l", &cas_d, &server_key,
-								  &server_key_len, &key, &key_len, &value, &expiration) == FAILURE) {
+		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "dssz|ll", &cas_d, &server_key,
+								  &server_key_len, &key, &key_len, &value, &expiration, &udf_flags) == FAILURE) {
 			return;
 		}
 	} else {
-		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "dsz|l", &cas_d, &key, &key_len,
-								  &value, &expiration) == FAILURE) {
+		if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "dsz|ll", &cas_d, &key, &key_len,
+								  &value, &expiration, &udf_flags) == FAILURE) {
 			return;
 		}
 	}
@@ -1524,6 +1598,18 @@ static void php_memc_cas_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
 		flags |= MEMC_VAL_COMPRESSED;
 	}
 
+	/*
+	 * php_memcached uses 8 bits internally to store type, compression and serialization info.
+	 * We use 8 upper bits to store user defined flags.
+	 */
+	if (udf_flags > 0) {
+		if (udf_flags > (MEMC_UDF_MASK>>8)) {
+			php_error_docref(NULL TSRMLS_CC, E_WARNING, "udf_flags will be limited to %d", (MEMC_UDF_MASK>>8));
+		}
+
+		MEMC_UDF_SET(flags, udf_flags);
+	}
+
 	payload = php_memc_zval_to_payload(value, &payload_len, &flags, m_obj->serializer, m_obj->compression_type TSRMLS_CC);
 	if (payload == NULL) {
 		i_obj->rescode = MEMC_RES_PAYLOAD_FAILURE;
@@ -1544,7 +1630,7 @@ static void php_memc_cas_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key)
 }
 /* }}} */
 
-/* {{{ Memcached::cas(double cas_token, string key, mixed value [, int expiration ])
+/* {{{ Memcached::cas(double cas_token, string key, mixed value [, int expiration [, int udf_flags ] ])
    Sets the value for the given key, failing if the cas_token doesn't match the one in memcache */
 PHP_METHOD(Memcached, cas)
 {
@@ -1552,7 +1638,7 @@ PHP_METHOD(Memcached, cas)
 }
 /* }}} */
 
-/* {{{ Memcached::casByKey(double cas_token, string server_key, string key, mixed value [, int expiration ])
+/* {{{ Memcached::casByKey(double cas_token, string server_key, string key, mixed value [, int expiration [, int udf_flags ] ])
    Sets the value for the given key on the server identified by the server_key, failing if the cas_token doesn't match the one in memcache */
 PHP_METHOD(Memcached, casByKey)
 {
@@ -3360,6 +3446,9 @@ static int php_memc_do_result_callback(zval *zmemc_obj, zend_fcall_info *fci,
 	if (cas != 0) {
 		add_assoc_double_ex(z_result, ZEND_STRS("cas"), (double)cas);
 	}
+	if ((flags & MEMC_UDF_MASK) != 0) {
+		add_assoc_long_ex(z_result, ZEND_STRS("flags"), MEMC_UDF_GET(flags));
+	}
 
 	if (zend_call_function(fci, fcc TSRMLS_CC) == FAILURE) {
 		php_error_docref(NULL TSRMLS_CC, E_WARNING, "could not invoke result callback");
@@ -3391,27 +3480,31 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_INFO_EX(arginfo_get, 0, 0, 1)
 	ZEND_ARG_INFO(0, key)
 	ZEND_ARG_INFO(0, cache_cb)
-	ZEND_ARG_INFO(1, cas_token)
+	ZEND_ARG_INFO(2, cas_token)
+	ZEND_ARG_INFO(1, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_getByKey, 0, 0, 2)
 	ZEND_ARG_INFO(0, server_key)
 	ZEND_ARG_INFO(0, key)
 	ZEND_ARG_INFO(0, cache_cb)
-	ZEND_ARG_INFO(1, cas_token)
+	ZEND_ARG_INFO(2, cas_token)
+	ZEND_ARG_INFO(1, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_getMulti, 0, 0, 1)
 	ZEND_ARG_ARRAY_INFO(0, keys, 0)
-	ZEND_ARG_INFO(1, cas_tokens)
+	ZEND_ARG_INFO(2, cas_tokens)
 	ZEND_ARG_INFO(0, flags)
+	ZEND_ARG_INFO(1, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_getMultiByKey, 0, 0, 2)
 	ZEND_ARG_INFO(0, server_key)
 	ZEND_ARG_ARRAY_INFO(0, keys, 0)
-	ZEND_ARG_INFO(1, cas_tokens)
+	ZEND_ARG_INFO(2, cas_tokens)
 	ZEND_ARG_INFO(0, flags)
+	ZEND_ARG_INFO(1, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_getDelayed, 0, 0, 1)
@@ -3437,6 +3530,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_set, 0, 0, 2)
 	ZEND_ARG_INFO(0, key)
 	ZEND_ARG_INFO(0, value)
 	ZEND_ARG_INFO(0, expiration)
+	ZEND_ARG_INFO(0, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_setByKey, 0, 0, 3)
@@ -3444,6 +3538,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_setByKey, 0, 0, 3)
 	ZEND_ARG_INFO(0, key)
 	ZEND_ARG_INFO(0, value)
 	ZEND_ARG_INFO(0, expiration)
+	ZEND_ARG_INFO(0, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_touch, 0, 0, 2)
@@ -3460,18 +3555,21 @@ ZEND_END_ARG_INFO()
 ZEND_BEGIN_ARG_INFO_EX(arginfo_setMulti, 0, 0, 1)
 	ZEND_ARG_ARRAY_INFO(0, items, 0)
 	ZEND_ARG_INFO(0, expiration)
+	ZEND_ARG_INFO(0, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_setMultiByKey, 0, 0, 2)
 	ZEND_ARG_INFO(0, server_key)
 	ZEND_ARG_ARRAY_INFO(0, items, 0)
 	ZEND_ARG_INFO(0, expiration)
+	ZEND_ARG_INFO(0, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_add, 0, 0, 2)
 	ZEND_ARG_INFO(0, key)
 	ZEND_ARG_INFO(0, value)
 	ZEND_ARG_INFO(0, expiration)
+	ZEND_ARG_INFO(0, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_addByKey, 0, 0, 3)
@@ -3479,12 +3577,14 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_addByKey, 0, 0, 3)
 	ZEND_ARG_INFO(0, key)
 	ZEND_ARG_INFO(0, value)
 	ZEND_ARG_INFO(0, expiration)
+	ZEND_ARG_INFO(0, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_replace, 0, 0, 2)
 	ZEND_ARG_INFO(0, key)
 	ZEND_ARG_INFO(0, value)
 	ZEND_ARG_INFO(0, expiration)
+	ZEND_ARG_INFO(0, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_replaceByKey, 0, 0, 3)
@@ -3492,6 +3592,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_replaceByKey, 0, 0, 3)
 	ZEND_ARG_INFO(0, key)
 	ZEND_ARG_INFO(0, value)
 	ZEND_ARG_INFO(0, expiration)
+	ZEND_ARG_INFO(0, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_append, 0, 0, 2)
@@ -3525,6 +3626,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_cas, 0, 0, 3)
 	ZEND_ARG_INFO(0, key)
 	ZEND_ARG_INFO(0, value)
 	ZEND_ARG_INFO(0, expiration)
+	ZEND_ARG_INFO(0, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_casByKey, 0, 0, 4)
@@ -3533,6 +3635,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_casByKey, 0, 0, 4)
 	ZEND_ARG_INFO(0, key)
 	ZEND_ARG_INFO(0, value)
 	ZEND_ARG_INFO(0, expiration)
+	ZEND_ARG_INFO(0, udf_flags)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_delete, 0, 0, 1)
diff --git a/tests/cas.phpt b/tests/cas.phpt
index fc14842b..09b436e0 100644
--- a/tests/cas.phpt
+++ b/tests/cas.phpt
@@ -30,6 +30,25 @@ if ($v !== 11) {
 	echo "Wanted cas_test to be 11, value is: ";
 	var_dump($v);
 }
+
+$v = $m->get('cas_test', null, 2);
+if ($v != 11) {
+	echo "Failed to get the value with \$cas_token passed by value (2)\n";
+	return;
+}
+
+$v = $m->get('cas_test', null, null);
+if ($v != 11) {
+	echo "Failed to get the value with \$cas_token passed by value (null)\n";
+	return;
+}
+
+$v = $m->get('cas_test', null, $data = array(2, 4));
+if ($v != 11 || $data !== array(2, 4)) {
+	echo "Failed to get the value with \$cas_token passed by value (\$data = array(2, 4))\n";
+	return;
+}
+
 echo "OK\n";
 ?>
 --EXPECT--
diff --git a/tests/cas_multi.phpt b/tests/cas_multi.phpt
index d180d779..e4c9e0f3 100644
--- a/tests/cas_multi.phpt
+++ b/tests/cas_multi.phpt
@@ -45,6 +45,33 @@ foreach ($data as $key => $v) {
 	}
 }
 
+if (array_keys($actual) !== array_keys($data)) {
+	echo "missing value(s)\n";
+	echo "data :";
+	var_dump($data);
+	echo "actual data: ";
+	var_dump($actual);
+	return;
+}
+
+$actual = $m->getMulti(array_keys($data), 2);
+if (array_keys($actual) !== array_keys($data)) {
+	echo "Failed to getMulti \$cas_token passed by value (2)\n";
+	return;
+}
+
+$actual = $m->getMulti(array_keys($data), null);
+if (array_keys($actual) !== array_keys($data)) {
+	echo "Failed to getMulti \$cas_token passed by value (null)\n";
+	return;
+}
+
+$actual = $m->getMulti(array_keys($data), $cas_tokens = array(2, 4));
+if (array_keys($actual) !== array_keys($data) || $cas_tokens !== array(2, 4)) {
+	echo "Failed to getMulti \$cas_token passed by value (\$cas_tokens = array(2, 4))\n";
+	return;
+}
+
 echo "OK\n";
 
 ?>