diff --git a/tests/unit/framework/caching/ApcCacheTest.php b/tests/unit/framework/caching/ApcCacheTest.php
index 6018ce7..20a1cc8 100644
--- a/tests/unit/framework/caching/ApcCacheTest.php
+++ b/tests/unit/framework/caching/ApcCacheTest.php
@@ -21,9 +21,17 @@ class ApcCacheTest extends CacheTest
 			$this->markTestSkipped("APC cli is not enabled. Skipping.");
 		}
 
+		if(!ini_get("apc.enabled") || !ini_get("apc.enable_cli")) {
+			$this->markTestSkipped("APC is installed but not enabled. Skipping.");
+		}
+
 		if ($this->_cacheInstance === null) {
 			$this->_cacheInstance = new ApcCache();
 		}
 		return $this->_cacheInstance;
 	}
+
+	// TODO there seems to be a problem with APC returning cached value even if it is expired.
+	// TODO makes test fail on PHP 5.3.10-1ubuntu3.6 with Suhosin-Patch (cli) -- cebe
+	// TODO http://drupal.org/node/1278292
 }
diff --git a/tests/unit/framework/caching/CacheTest.php b/tests/unit/framework/caching/CacheTest.php
index a17f126..6a9632c 100644
--- a/tests/unit/framework/caching/CacheTest.php
+++ b/tests/unit/framework/caching/CacheTest.php
@@ -18,19 +18,46 @@ abstract class CacheTest extends TestCase
 		parent::setUp();
 		$this->mockApplication();
 	}
-	
+
+	/**
+	 * @return Cache
+	 */
+	public function prepare()
+	{
+		$cache = $this->getCacheInstance();
+
+		$cache->flush();
+		$cache->set('string_test', 'string_test');
+		$cache->set('number_test', 42);
+		$cache->set('array_test', array('array_test' => 'array_test'));
+		$cache['arrayaccess_test'] = new \stdClass();
+
+		return $cache;
+	}
+
+	/**
+	 * default value of cache prefix is application id
+	 */
+	public function testKeyPrefix()
+	{
+		$cache = $this->getCacheInstance();
+		$this->assertNotNull(\Yii::$app->id);
+		$this->assertEquals(\Yii::$app->id, $cache->keyPrefix);
+	}
+
 	public function testSet()
 	{
 		$cache = $this->getCacheInstance();
+
 		$this->assertTrue($cache->set('string_test', 'string_test'));
 		$this->assertTrue($cache->set('number_test', 42));
 		$this->assertTrue($cache->set('array_test', array('array_test' => 'array_test')));
-		$cache['arrayaccess_test'] = new \stdClass();
 	}
 
 	public function testGet()
 	{
-		$cache = $this->getCacheInstance();
+		$cache = $this->prepare();
+
 		$this->assertEquals('string_test', $cache->get('string_test'));
 
 		$this->assertEquals(42, $cache->get('number_test'));
@@ -38,51 +65,82 @@ abstract class CacheTest extends TestCase
 		$array = $cache->get('array_test');
 		$this->assertArrayHasKey('array_test', $array);
 		$this->assertEquals('array_test', $array['array_test']);
+	}
 
+	public function testArrayAccess()
+	{
+		$cache = $this->getCacheInstance();
+
+		$cache['arrayaccess_test'] = new \stdClass();
 		$this->assertInstanceOf('stdClass', $cache['arrayaccess_test']);
 	}
 
-	public function testMget()
+	public function testGetNonExistent()
 	{
 		$cache = $this->getCacheInstance();
+
+		$this->assertFalse($cache->get('non_existent_key'));
+	}
+
+	public function testStoreSpecialValues()
+	{
+		$cache = $this->getCacheInstance();
+
+		$this->assertTrue($cache->set('null_value', null));
+		$this->assertNull($cache->get('null_value'));
+
+		$this->assertTrue($cache->set('bool_value', true));
+		$this->assertTrue($cache->get('bool_value'));
+	}
+
+	public function testMget()
+	{
+		$cache = $this->prepare();
+
 		$this->assertEquals(array('string_test' => 'string_test', 'number_test' => 42), $cache->mget(array('string_test', 'number_test')));
+		// ensure that order does not matter
+		$this->assertEquals(array('number_test' => 42, 'string_test' => 'string_test'), $cache->mget(array('number_test', 'string_test')));
+		$this->assertEquals(array('number_test' => 42, 'non_existent_key' => null), $cache->mget(array('number_test', 'non_existent_key')));
 	}
 
 	public function testExpire()
 	{
 		$cache = $this->getCacheInstance();
+
 		$this->assertTrue($cache->set('expire_test', 'expire_test', 2));
 		sleep(1);
 		$this->assertEquals('expire_test', $cache->get('expire_test'));
 		sleep(2);
-		$this->assertEquals(false, $cache->get('expire_test'));
+		$this->assertFalse($cache->get('expire_test'));
 	}
 
 	public function testAdd()
 	{
-		$cache = $this->getCacheInstance();
+		$cache = $this->prepare();
 
 		// should not change existing keys
 		$this->assertFalse($cache->add('number_test', 13));
 		$this->assertEquals(42, $cache->get('number_test'));
 
-		// should store data is it's not there yet
+		// should store data if it's not there yet
+		$this->assertFalse($cache->get('add_test'));
 		$this->assertTrue($cache->add('add_test', 13));
 		$this->assertEquals(13, $cache->get('add_test'));
 	}
 
 	public function testDelete()
 	{
-		$cache = $this->getCacheInstance();
+		$cache = $this->prepare();
 
+		$this->assertNotNull($cache->get('number_test'));
 		$this->assertTrue($cache->delete('number_test'));
-		$this->assertEquals(null, $cache->get('number_test'));
+		$this->assertFalse($cache->get('number_test'));
 	}
 
 	public function testFlush()
 	{
-		$cache = $this->getCacheInstance();
+		$cache = $this->prepare();
 		$this->assertTrue($cache->flush());
-		$this->assertEquals(null, $cache->get('add_test'));
+		$this->assertFalse($cache->get('number_test'));
 	}
 }
diff --git a/tests/unit/framework/caching/MemCachedTest.php b/tests/unit/framework/caching/MemCachedTest.php
index 66dfb50..bce23ba 100644
--- a/tests/unit/framework/caching/MemCachedTest.php
+++ b/tests/unit/framework/caching/MemCachedTest.php
@@ -4,7 +4,7 @@ use yii\caching\MemCache;
 use yiiunit\TestCase;
 
 /**
- * Class for testing memcache cache backend
+ * Class for testing memcached cache backend
  */
 class MemCachedTest extends CacheTest
 {