diff --git a/apc_cache.c b/apc_cache.c
index 480dd001..7e7e7a19 100644
--- a/apc_cache.c
+++ b/apc_cache.c
@@ -1218,6 +1218,9 @@ PHP_APCU_API zend_bool apc_cache_defense(apc_cache_t *cache, zend_string *key, t
 PHP_APCU_API void apc_cache_serializer(apc_cache_t* cache, const char* name) {
 	if (cache && !cache->serializer) {
 		cache->serializer = apc_find_serializer(name);
+		if (strcmp(name, "default") != 0 && !cache->serializer) {
+			php_error_docref(NULL, E_WARNING, "apc_cache_serializer: serializer \"%s\" is not supported", name);
+		}
 	}
 } /* }}} */
 
diff --git a/tests/serializer_invalid.phpt b/tests/serializer_invalid.phpt
new file mode 100644
index 00000000..bd4c662e
--- /dev/null
+++ b/tests/serializer_invalid.phpt
@@ -0,0 +1,12 @@
+--TEST--
+Serializer: invalid pattern.
+--SKIPIF--
+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>
+--INI--
+apc.enabled=1
+apc.enable_cli=1
+apc.serializer=igbinary
+--FILE--
+<?php
+--EXPECT--
+Warning: Unknown: apc_cache_serializer: serializer "igbinary" is not supported in Unknown on line 0
diff --git a/tests/serializer_valid.phpt b/tests/serializer_valid.phpt
new file mode 100644
index 00000000..d09f6b80
--- /dev/null
+++ b/tests/serializer_valid.phpt
@@ -0,0 +1,11 @@
+--TEST--
+Serializer: valid pattern.
+--SKIPIF--
+<?php require_once(dirname(__FILE__) . '/skipif.inc'); ?>
+--INI--
+apc.enabled=1
+apc.enable_cli=1
+apc.serializer=php
+--FILE--
+<?php
+--EXPECT--