diff --git a/src/Storage/Adapter/Apc.php b/src/Storage/Adapter/Apc.php
index b380672f4..939fb588d 100644
--- a/src/Storage/Adapter/Apc.php
+++ b/src/Storage/Adapter/Apc.php
@@ -143,7 +143,6 @@ public function getIterator()
         $options = $this->getOptions();
         $prefix  = $options->getNamespace() . $options->getNamespaceSeparator();
         $pattern = '/^' . preg_quote($prefix, '/') . '/';
-        $format  = 0;
 
         $baseIt = new BaseApcIterator('user', $pattern, 0, 1, \APC_LIST_ACTIVE);
         return new ApcIterator($this, $baseIt, $prefix);
diff --git a/src/Storage/Adapter/Filesystem.php b/src/Storage/Adapter/Filesystem.php
index 4454c7d05..4f0f5f385 100644
--- a/src/Storage/Adapter/Filesystem.php
+++ b/src/Storage/Adapter/Filesystem.php
@@ -193,8 +193,6 @@ public function clearByNamespace($namespace)
         . str_repeat(\DIRECTORY_SEPARATOR . $nsPrefix . '*', $options->getDirLevel())
         . \DIRECTORY_SEPARATOR . $nsPrefix . '*';
         $glob = new GlobIterator($path, $flags);
-        $time = time();
-        $ttl  = $options->getTtl();
 
         ErrorHandler::start();
         foreach ($glob as $pathname) {
@@ -227,8 +225,6 @@ public function clearByPrefix($prefix)
             . str_repeat(\DIRECTORY_SEPARATOR . $nsPrefix . '*', $options->getDirLevel())
             . \DIRECTORY_SEPARATOR . $nsPrefix . $prefix . '*';
         $glob = new GlobIterator($path, $flags);
-        $time = time();
-        $ttl  = $options->getTtl();
 
         ErrorHandler::start();
         foreach ($glob as $pathname) {
@@ -317,8 +313,6 @@ public function clearByTags(array $tags, $disjunction = false)
             . str_repeat(\DIRECTORY_SEPARATOR . $prefix . '*', $options->getDirLevel())
             . \DIRECTORY_SEPARATOR . $prefix . '*.tag';
         $glob = new GlobIterator($path, $flags);
-        $time = time();
-        $ttl  = $options->getTtl();
 
         foreach ($glob as $pathname) {
             $diff = array_diff($tags, explode("\n", $this->getFileContent($pathname)));
@@ -884,7 +878,6 @@ public function replaceItems(array $keyValuePairs)
      */
     protected function internalSetItem(& $normalizedKey, & $value)
     {
-        $options  = $this->getOptions();
         $filespec = $this->getFileSpec($normalizedKey);
         $this->prepareDirectoryStructure($filespec);
 
@@ -903,7 +896,6 @@ protected function internalSetItem(& $normalizedKey, & $value)
      */
     protected function internalSetItems(array & $normalizedKeyValuePairs)
     {
-        $baseOptions = $this->getOptions();
         $oldUmask    = null;
 
         // create an associated array of files and contents to write
diff --git a/src/Storage/Adapter/Memcached.php b/src/Storage/Adapter/Memcached.php
index d0f5a955b..530bae039 100644
--- a/src/Storage/Adapter/Memcached.php
+++ b/src/Storage/Adapter/Memcached.php
@@ -302,7 +302,7 @@ protected function internalGetMetadatas(array & $normalizedKeys)
             throw $this->getExceptionByResultCode($this->memcached->getResultCode());
         }
 
-        foreach ($result as $key => & $value) {
+        foreach ($result as & $value) {
             $value = array();
         }
 
diff --git a/src/Storage/Plugin/Serializer.php b/src/Storage/Plugin/Serializer.php
index ec8c46ba8..c90d86077 100644
--- a/src/Storage/Plugin/Serializer.php
+++ b/src/Storage/Plugin/Serializer.php
@@ -218,7 +218,6 @@ public function onIncrementItemsPre(Event $event)
         }
 
         $failedKeys = $storage->setItems($keyValuePairs);
-        $result     = array();
         foreach ($failedKeys as $failedKey) {
             unset($keyValuePairs[$failedKey]);
         }