diff --git a/src/Assetic/Filter/CssImportFilter.php b/src/Assetic/Filter/CssImportFilter.php
index 6278f812b..30157404d 100644
--- a/src/Assetic/Filter/CssImportFilter.php
+++ b/src/Assetic/Filter/CssImportFilter.php
@@ -1,22 +1,29 @@
 <?php namespace October\Rain\Assetic\Filter;
 
+use October\Rain\Assetic\Filter\HashableInterface;
 use October\Rain\Assetic\Asset\AssetInterface;
 use October\Rain\Assetic\Asset\FileAsset;
 use October\Rain\Assetic\Asset\HttpAsset;
 use October\Rain\Assetic\Factory\AssetFactory;
+use October\Rain\Assetic\Util\CssUtils;
 
 /**
- * CssImportFilter inlines imported stylesheets.
+ * CssImportFilter converts imported stylesheets to inline.
  *
  * @author Kris Wallsmith <kris.wallsmith@gmail.com>
  */
-class CssImportFilter extends BaseCssFilter implements DependencyExtractorInterface
+class CssImportFilter extends BaseCssFilter implements HashableInterface, DependencyExtractorInterface
 {
     /**
      * @var mixed importFilter
      */
     protected $importFilter;
 
+    /**
+     * @var string lastHash
+     */
+    protected $lastHash;
+
     /**
      * __construct
      *
@@ -37,29 +44,29 @@ public function filterLoad(AssetInterface $asset)
         $sourcePath = $asset->getSourcePath();
 
         $callback = function ($matches) use ($importFilter, $sourceRoot, $sourcePath) {
-            if (!$matches['url'] || null === $sourceRoot) {
+            if (!$matches['url'] || $sourceRoot === null) {
                 return $matches[0];
             }
 
             $importRoot = $sourceRoot;
 
-            if (false !== strpos($matches['url'], '://')) {
-                // absolute
+            // Absolute
+            if (strpos($matches['url'], '://') !== false) {
                 list($importScheme, $tmp) = explode('://', $matches['url'], 2);
                 list($importHost, $importPath) = explode('/', $tmp, 2);
                 $importRoot = $importScheme.'://'.$importHost;
             }
-            elseif (0 === strpos($matches['url'], '//')) {
-                // protocol-relative
+            // Protocol-relative
+            elseif (strpos($matches['url'], '//') === 0) {
                 list($importHost, $importPath) = explode('/', substr($matches['url'], 2), 2);
                 $importRoot = '//'.$importHost;
             }
-            elseif ('/' == $matches['url'][0]) {
-                // root-relative
+            // Root-relative
+            elseif ($matches['url'][0] == '/') {
                 $importPath = substr($matches['url'], 1);
             }
-            elseif (null !== $sourcePath) {
-                // document-relative
+            // Document-relative
+            elseif ($sourcePath !== null) {
                 $importPath = $matches['url'];
                 if ('.' != $sourceDir = dirname($sourcePath)) {
                     $importPath = $sourceDir.'/'.$importPath;
@@ -70,15 +77,15 @@ public function filterLoad(AssetInterface $asset)
             }
 
             $importSource = $importRoot.'/'.$importPath;
-            if (false !== strpos($importSource, '://') || 0 === strpos($importSource, '//')) {
-                $import = new HttpAsset($importSource, array($importFilter), true);
+            if (strpos($importSource, '://') !== false || strpos($importSource, '//') === 0) {
+                $import = new HttpAsset($importSource, [$importFilter], true);
             }
-            elseif ('css' != pathinfo($importPath, PATHINFO_EXTENSION) || !file_exists($importSource)) {
-                // ignore non-css and non-existant imports
+            // Ignore non-css and non-existent imports
+            elseif (pathinfo($importPath, PATHINFO_EXTENSION) != 'css' || !file_exists($importSource)) {
                 return $matches[0];
             }
             else {
-                $import = new FileAsset($importSource, array($importFilter), $importRoot, $importPath);
+                $import = new FileAsset($importSource, [$importFilter], $importRoot, $importPath);
             }
 
             $import->setTargetPath($sourcePath);
@@ -92,7 +99,7 @@ public function filterLoad(AssetInterface $asset)
         do {
             $content = $this->filterImports($content, $callback);
             $hash = md5($content);
-        } while ($lastHash != $hash && $lastHash = $hash);
+        } while ($lastHash != $hash && ($lastHash = $hash));
 
         $asset->setContent($content);
     }
@@ -105,11 +112,84 @@ public function filterDump(AssetInterface $asset)
     }
 
     /**
-     * getChildren
+     * hashAsset
+     */
+    public function hashAsset($asset, $localPath)
+    {
+        $factory = new AssetFactory($localPath);
+        $children = $this->getAllChildren($factory, file_get_contents($asset), dirname($asset));
+
+        $allFiles = [];
+        foreach ($children as $child) {
+            $allFiles[] = $child;
+        }
+
+        $modified = [];
+        foreach ($allFiles as $file) {
+            $modified[] = $file->getLastModified();
+        }
+
+        return md5(implode('|', $modified));
+    }
+
+    /**
+     * setHash
+     */
+    public function setHash($hash)
+    {
+        $this->lastHash = $hash;
+    }
+
+    /**
+     * hash generated for the object
+     * @return string
+     */
+    public function hash()
+    {
+        return $this->lastHash ?: serialize($this);
+    }
+
+    /**
+     * getAllChildren loads all children recursively
+     */
+    public function getAllChildren(AssetFactory $factory, $content, $loadPath = null)
+    {
+        $children = (new static)->getChildren($factory, $content, $loadPath);
+
+        foreach ($children as $child) {
+            $childContent = file_get_contents($child->getSourceRoot().'/'.$child->getSourcePath());
+            $children = array_merge($children, (new static)->getChildren($factory, $childContent, $loadPath.'/'.dirname($child->getSourcePath())));
+        }
+
+        return $children;
+    }
+
+    /**
+     * getChildren only returns one level of children
      */
     public function getChildren(AssetFactory $factory, $content, $loadPath = null)
     {
-        // todo
-        return [];
+        if (!$loadPath) {
+            return [];
+        }
+
+        $children = [];
+        foreach (CssUtils::extractImports($content) as $reference) {
+            // Strict check, only allow .css imports
+            if (substr($reference, -4) !== '.css') {
+                continue;
+            }
+
+            if (file_exists($file = $loadPath.'/'.$reference)) {
+                $coll = $factory->createAsset($file, [], ['root' => $loadPath]);
+                foreach ($coll as $leaf) {
+                    $leaf->ensureFilter($this);
+                    $children[] = $leaf;
+                    break;
+                }
+            }
+        }
+
+        return $children;
     }
 }
diff --git a/src/Assetic/Filter/LessCompiler.php b/src/Assetic/Filter/LessCompiler.php
index 8fa7705f1..1db6ff61d 100644
--- a/src/Assetic/Filter/LessCompiler.php
+++ b/src/Assetic/Filter/LessCompiler.php
@@ -17,15 +17,27 @@
  */
 class LessCompiler implements FilterInterface, HashableInterface, DependencyExtractorInterface
 {
+    /**
+     * @var array presets
+     */
     protected $presets = [];
 
+    /**
+     * @var string lastHash
+     */
     protected $lastHash;
 
+    /**
+     * setPresets
+     */
     public function setPresets(array $presets)
     {
         $this->presets = $presets;
     }
 
+    /**
+     * filterLoad
+     */
     public function filterLoad(AssetInterface $asset)
     {
         $parser = new Less_Parser();
@@ -41,10 +53,16 @@ public function filterLoad(AssetInterface $asset)
         $asset->setContent($parser->getCss());
     }
 
+    /**
+     * filterDump
+     */
     public function filterDump(AssetInterface $asset)
     {
     }
 
+    /**
+     * hashAsset
+     */
     public function hashAsset($asset, $localPath)
     {
         $factory = new AssetFactory($localPath);
@@ -55,21 +73,24 @@ public function hashAsset($asset, $localPath)
             $allFiles[] = $child;
         }
 
-        $modifieds = [];
+        $modified = [];
         foreach ($allFiles as $file) {
-            $modifieds[] = $file->getLastModified();
+            $modified[] = $file->getLastModified();
         }
 
-        return md5(implode('|', $modifieds));
+        return md5(implode('|', $modified));
     }
 
+    /**
+     * setHash
+     */
     public function setHash($hash)
     {
         $this->lastHash = $hash;
     }
 
     /**
-     * Generates a hash for the object
+     * hash generated for the object
      * @return string
      */
     public function hash()
@@ -78,7 +99,7 @@ public function hash()
     }
 
     /**
-     * Load children recusive
+     * getChildren loads children recursively
      */
     public function getChildren(AssetFactory $factory, $content, $loadPath = null)
     {
diff --git a/src/Assetic/Filter/LessphpFilter.php b/src/Assetic/Filter/LessphpFilter.php
index d91d2270b..defb0fae1 100644
--- a/src/Assetic/Filter/LessphpFilter.php
+++ b/src/Assetic/Filter/LessphpFilter.php
@@ -118,7 +118,7 @@ public function filterDump(AssetInterface $asset)
     public function getChildren(AssetFactory $factory, $content, $loadPath = null)
     {
         $loadPaths = $this->loadPaths;
-        if (null !== $loadPath) {
+        if ($loadPath !== null) {
             $loadPaths[] = $loadPath;
         }
 
@@ -128,28 +128,26 @@ public function getChildren(AssetFactory $factory, $content, $loadPath = null)
 
         $children = [];
         foreach (LessUtils::extractImports($content) as $reference) {
-            if ('.css' === substr($reference, -4)) {
+            if (substr($reference, -4) === '.css') {
                 // skip normal css imports
                 // todo: skip imports with media queries
                 continue;
             }
 
-            if ('.less' !== substr($reference, -5)) {
+            if (substr($reference, -5) !== '.less') {
                 $reference .= '.less';
             }
 
             foreach ($loadPaths as $loadPath) {
                 if (file_exists($file = $loadPath.'/'.$reference)) {
-                    $coll = $factory->createAsset($file, array(), array('root' => $loadPath));
+                    $coll = $factory->createAsset($file, [], ['root' => $loadPath]);
                     foreach ($coll as $leaf) {
                         $leaf->ensureFilter($this);
                         $children[] = $leaf;
-                        goto next_reference;
+                        break 2;
                     }
                 }
             }
-
-            next_reference:
         }
 
         return $children;
diff --git a/src/Assetic/Traits/HasDeepHasher.php b/src/Assetic/Traits/HasDeepHasher.php
index 677504976..3989b18ae 100644
--- a/src/Assetic/Traits/HasDeepHasher.php
+++ b/src/Assetic/Traits/HasDeepHasher.php
@@ -4,7 +4,7 @@
 use October\Rain\Assetic\Factory\AssetFactory;
 
 /**
- * Combiner helper class
+ * HasDeepHasher checks if imports have changed their content and busts the cache
  *
  * @package october/assetic
  * @author Alexey Bobkov, Samuel Georges
@@ -48,7 +48,6 @@ public function getDeepHashFromAssets($assets)
 
     /**
      * setHashOnCombinerFilters busts the cache based on a different cache key.
-     * @return void
      */
     protected function setDeepHashKeyOnFilters($hash)
     {