diff --git a/.scrutinizer.yml b/.scrutinizer.yml
new file mode 100644
index 0000000..87fda20
--- /dev/null
+++ b/.scrutinizer.yml
@@ -0,0 +1,2 @@
+tools:
+  external_code_coverage: true
diff --git a/.travis.yml b/.travis.yml
index d17bbe1..2a3fad3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -27,4 +27,8 @@ before_script:
   - composer install
 
 script:
-  - vendor/bin/phpunit --coverage-text --configuration phpunit.xml
+  - vendor/bin/phpunit --coverage-text --configuration phpunit.xml --coverage-clover=coverage.clover
+
+after_script:
+    - wget https://scrutinizer-ci.com/ocular.phar
+    - php ocular.phar code-coverage:upload --format=php-clover coverage.clover
diff --git a/README.md b/README.md
index 8776b36..a65b9df 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,8 @@
-# Weak-referenced data structures for PHP [![Build Status](https://travis-ci.org/pinepain/php-weak-lib.svg)](https://travis-ci.org/pinepain/php-weak-lib)
+# Weak-referenced data structures for PHP
+
+[![Build Status](https://travis-ci.org/pinepain/php-weak-lib.svg)](https://travis-ci.org/pinepain/php-weak-lib)
+[![Scrutinizer Code Quality](https://scrutinizer-ci.com/g/pinepain/php-weak-lib/badges/quality-score.png)](https://scrutinizer-ci.com/g/pinepain/php-weak-lib)
+[![Code Coverage](https://scrutinizer-ci.com/g/pinepain/php-weak-lib/badges/coverage.png)](https://scrutinizer-ci.com/g/pinepain/php-weak-lib)
 
 This library is based on [php-weak][php-weak-ext] PHP extension and provides various weak data structures:
 
diff --git a/src/AbstractWeakMap.php b/src/AbstractWeakMap.php
new file mode 100644
index 0000000..383079b
--- /dev/null
+++ b/src/AbstractWeakMap.php
@@ -0,0 +1,169 @@
+<?php
+
+/*
+ * This file is part of the pinepain/php-weak-lib PHP library.
+ *
+ * Copyright (c) 2016 Bogdan Padalko <zaq178miami@gmail.com>
+ *
+ * Licensed under the MIT license: http://opensource.org/licenses/MIT
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code or visit http://opensource.org/licenses/MIT
+ */
+
+namespace Weak;
+
+use RuntimeException;
+use SplObjectStorage;
+
+abstract class AbstractWeakMap extends SplObjectStorage
+{
+    const WEAK_KEY = 1;
+    const WEAK_VAL = 2;
+
+    protected $behavior = 0;
+
+    /** {@inheritdoc} */
+    public function attach($object, $data = null)
+    {
+        if ($this->behavior & self::WEAK_KEY) {
+            $object = $this->buildWeakKey($object);
+        }
+
+        if ($this->behavior & self::WEAK_VAL) {
+            $data = $this->buildWeakValue($object, $data);
+        }
+
+        parent::attach($object, $data);
+    }
+
+    /** {@inheritdoc} */
+    public function current()
+    {
+        $object = parent::current();
+
+        if ($this->behavior & self::WEAK_KEY) {
+            $object = $this->extractWeakObject($object);
+        }
+
+        /* In some rare cases (it should never happen normally) orphaned weak reference may occurs in storage, so
+         * so current object here MAY be null
+         */
+
+        return $object;
+    }
+
+    /** {@inheritdoc} */
+    public function addAll($storage)
+    {
+        foreach ($storage as $obj) {
+            $this->attach($obj, $storage[$obj]);
+        }
+    }
+
+    /** {@inheritdoc} */
+    public function removeAllExcept($storage)
+    {
+        $pending_removal = new \SplObjectStorage();
+
+        foreach ($this as $obj) {
+            if (!$storage->contains($obj)) {
+                $pending_removal->attach($obj);
+            }
+        }
+
+        $this->removeAll($pending_removal);
+    }
+
+    /** {@inheritdoc} */
+    public function getHash($object)
+    {
+        if ($this->behavior & self::WEAK_KEY) {
+            if ($object instanceof HashedReference) {
+                return $object->getHash();
+            }
+        }
+
+        return parent::getHash($object);
+    }
+
+    /** {@inheritdoc} */
+    public function getInfo()
+    {
+        $info = parent::getInfo();
+
+        if ($this->behavior & self::WEAK_VAL) {
+            $info = $this->extractWeakObject($info);
+        }
+
+        return $info;
+    }
+
+    /** {@inheritdoc} */
+    public function setInfo($data)
+    {
+        $object = $this->current();
+
+        if (!$object) {
+            return; // nothing to do
+        }
+
+        if ($this->behavior & self::WEAK_VAL) {
+            $data = $this->buildWeakValue($object, $data);
+        }
+
+        parent::setInfo($data);
+    }
+
+    /** {@inheritdoc} */
+    public function offsetSet($object, $data = null)
+    {
+        $this->attach($object, $data);
+    }
+
+    /** {@inheritdoc} */
+    public function offsetGet($object)
+    {
+        $info = parent::offsetGet($object);
+
+        if ($this->behavior & self::WEAK_VAL) {
+            $info = $this->extractWeakObject($info);
+        }
+
+        return $info;
+    }
+
+    protected function validateInfo($data)
+    {
+        if (!is_object($data)) {
+            throw new RuntimeException(static::class . ' expects data to be object, ' . gettype($data) . ' given');
+        }
+    }
+
+    protected function extractWeakObject($object)
+    {
+        if ($object instanceof Reference) {
+            $object = $object->get();
+        }
+
+        return $object;
+    }
+
+    protected function buildWeakKey($object)
+    {
+        $object = new HashedReference($object, [$this, 'detach'], 'spl_object_hash');
+
+        return $object;
+    }
+
+    protected function buildWeakValue($object, $data)
+    {
+        $this->validateInfo($data);
+
+        $data = new Reference($data, function () use ($object) {
+            $this->detach($object);
+        });
+
+        return $data;
+    }
+}
diff --git a/src/WeakKeyMap.php b/src/WeakKeyMap.php
index ad0a35a..1cfa399 100644
--- a/src/WeakKeyMap.php
+++ b/src/WeakKeyMap.php
@@ -13,69 +13,7 @@
 
 namespace Weak;
 
-use SplObjectStorage;
-
-class WeakKeyMap extends SplObjectStorage
+class WeakKeyMap extends AbstractWeakMap
 {
-    /** {@inheritdoc} */
-    public function attach($object, $data = null)
-    {
-        $object = new HashedReference($object, [$this, 'detach'], 'spl_object_hash');
-
-        parent::attach($object, $data);
-    }
-
-    /** {@inheritdoc} */
-    public function current()
-    {
-        $current = parent::current();
-
-        if ($current instanceof Reference) {
-            $current = $current->get();
-        }
-
-        /* In some rare cases (it should never happens normally) orphaned weak reference may occurs in storage, so
-         * so $current here MAY be null
-         */
-
-        return $current;
-    }
-
-    /** {@inheritdoc} */
-    public function offsetSet($object, $data = null)
-    {
-        $this->attach($object, $data);
-    }
-
-    /** {@inheritdoc} */
-    public function addAll($storage)
-    {
-        foreach ($storage as $obj) {
-            $this->attach($obj, $storage[$obj]);
-        }
-    }
-
-    /** {@inheritdoc} */
-    public function removeAllExcept($storage)
-    {
-        $pending_removal = new \SplObjectStorage();
-
-        foreach ($this as $obj) {
-            if (!$storage->contains($obj)) {
-                $pending_removal->attach($obj);
-            }
-        }
-
-        $this->removeAll($pending_removal);
-    }
-
-    /** {@inheritdoc} */
-    public function getHash($object)
-    {
-        if ($object instanceof HashedReference) {
-            return $object->getHash();
-        }
-
-        return parent::getHash($object);
-    }
+    protected $behavior = self::WEAK_KEY;
 }
diff --git a/src/WeakKeyValueMap.php b/src/WeakKeyValueMap.php
index 70a2444..da0a9dc 100644
--- a/src/WeakKeyValueMap.php
+++ b/src/WeakKeyValueMap.php
@@ -13,124 +13,7 @@
 
 namespace Weak;
 
-use RuntimeException;
-use SplObjectStorage;
-
-class WeakKeyValueMap extends SplObjectStorage
+class WeakKeyValueMap extends AbstractWeakMap
 {
-    /** {@inheritdoc} */
-    public function attach($object, $data = null)
-    {
-        $this->validateInfo($data);
-
-        $object = new HashedReference($object, [$this, 'detach'], 'spl_object_hash');
-
-        $data = new Reference($data, function () use ($object) {
-            $this->detach($object);
-        });
-
-        parent::attach($object, $data);
-    }
-
-    /** {@inheritdoc} */
-    public function current()
-    {
-        $current = parent::current();
-
-        if ($current instanceof Reference) {
-            $current = $current->get();
-        }
-
-        /* In some rare cases (it should never happens normally) orphaned weak reference may occurs in storage, so
-         * so $current here MAY be null
-         */
-
-        return $current;
-    }
-
-    /** {@inheritdoc} */
-    public function addAll($storage)
-    {
-        foreach ($storage as $obj) {
-            $this->attach($obj, $storage[$obj]);
-        }
-    }
-
-    public function removeAllExcept($storage)
-    {
-        $pending_removal = new \SplObjectStorage();
-
-        foreach ($this as $obj) {
-            if (!$storage->contains($obj)) {
-                $pending_removal->attach($obj);
-            }
-        }
-
-        $this->removeAll($pending_removal);
-    }
-
-    /** {@inheritdoc} */
-    public function getHash($object)
-    {
-        if ($object instanceof HashedReference) {
-            return $object->getHash();
-        }
-
-        return parent::getHash($object);
-    }
-
-    /** {@inheritdoc} */
-    public function getInfo()
-    {
-        $info = parent::getInfo(); // TODO: Change the autogenerated stub
-
-        if ($info instanceof Reference) {
-            $info = $info->get();
-        }
-
-        return $info;
-    }
-
-    /** {@inheritdoc} */
-    public function setInfo($data)
-    {
-        $this->validateInfo($data);
-
-        $object = $this->current();
-
-        if (!$object) {
-            return; // nothing to do
-        }
-
-        $data = new Reference($data, function () use ($object) {
-            $this->detach($object);
-        });
-
-        parent::setInfo($data);
-    }
-
-    /** {@inheritdoc} */
-    public function offsetSet($object, $data = null)
-    {
-        $this->attach($object, $data);
-    }
-
-    /** {@inheritdoc} */
-    public function offsetGet($object)
-    {
-        $info = parent::offsetGet($object); // TODO: Change the autogenerated stub
-
-        if ($info instanceof Reference) {
-            $info = $info->get();
-        }
-
-        return $info;
-    }
-
-    protected function validateInfo($data)
-    {
-        if (!is_object($data)) {
-            throw new RuntimeException(self::class . ' expects data to be object, ' . gettype($data) . ' given');
-        }
-    }
+    protected $behavior = self::WEAK_KEY | self::WEAK_VAL;
 }
diff --git a/src/WeakValueMap.php b/src/WeakValueMap.php
index 25c070b..17c72e1 100644
--- a/src/WeakValueMap.php
+++ b/src/WeakValueMap.php
@@ -13,83 +13,7 @@
 
 namespace Weak;
 
-use RuntimeException;
-use SplObjectStorage;
-
-class WeakValueMap extends SplObjectStorage
+class WeakValueMap extends AbstractWeakMap
 {
-    /** {@inheritdoc} */
-    public function attach($object, $data = null)
-    {
-        $this->validateInfo($data);
-
-        $data = new Reference($data, function () use ($object) {
-            $this->detach($object);
-        });
-
-        parent::attach($object, $data);
-    }
-
-    /** {@inheritdoc} */
-    public function addAll($storage)
-    {
-        foreach ($storage as $obj) {
-            $this->attach($obj, $storage[$obj]);
-        }
-    }
-
-    /** {@inheritdoc} */
-    public function getInfo()
-    {
-        $info = parent::getInfo(); // TODO: Change the autogenerated stub
-
-        if ($info instanceof Reference) {
-            $info = $info->get();
-        }
-
-        return $info;
-    }
-
-    /** {@inheritdoc} */
-    public function setInfo($data)
-    {
-        $this->validateInfo($data);
-
-        $object = $this->current();
-
-        if (!$object) {
-            return; // nothing to do
-        }
-
-        $data = new Reference($data, function () use ($object) {
-            $this->detach($object);
-        });
-
-        parent::setInfo($data);
-    }
-
-    /** {@inheritdoc} */
-    public function offsetSet($object, $data = null)
-    {
-        $this->attach($object, $data);
-    }
-
-    /** {@inheritdoc} */
-    public function offsetGet($object)
-    {
-        $info = parent::offsetGet($object); // TODO: Change the autogenerated stub
-
-        if ($info instanceof Reference) {
-            $info = $info->get();
-        }
-
-        return $info;
-    }
-
-    protected function validateInfo($data)
-    {
-        if (!is_object($data)) {
-            throw new RuntimeException(self::class . ' expects data to be object, ' . gettype($data) . ' given');
-        }
-    }
+    protected $behavior = self::WEAK_VAL;
 }
diff --git a/tests/WeakKeyValueMapTest.php b/tests/WeakKeyValueMapTest.php
index 7f51d18..451f404 100644
--- a/tests/WeakKeyValueMapTest.php
+++ b/tests/WeakKeyValueMapTest.php
@@ -196,6 +196,15 @@ public function testSetInfoWithNoCurrent()
         $this->assertSame($inf1, $map[$obj1]);
     }
 
+    public function testSetInfoNotObjectOnNonexistentCurrent()
+    {
+        $map = new WeakKeyValueMap();
+        $map->setInfo(null);
+
+        $this->assertTrue(true);
+    }
+
+
     /**
      * @expectedException \RuntimeException
      * @expectedExceptionMessage WeakKeyValueMap expects data to be object, NULL given
@@ -203,6 +212,12 @@ public function testSetInfoWithNoCurrent()
     public function testSetInfoNotObject()
     {
         $map = new WeakKeyValueMap();
+
+        $obj1 = new stdClass();
+        $inf1 = new stdClass();
+        $map->attach($obj1, $inf1);
+
+        $map->rewind();
         $map->setInfo(null);
     }
 
diff --git a/tests/WeakValueMapTest.php b/tests/WeakValueMapTest.php
index 69361f3..31e9733 100644
--- a/tests/WeakValueMapTest.php
+++ b/tests/WeakValueMapTest.php
@@ -166,6 +166,15 @@ public function testSetInfoWithNoCurrent()
         $this->assertSame($inf1, $map[$obj1]);
     }
 
+    public function testSetInfoNotObjectOnNonexistentCurrent()
+    {
+        $map = new WeakValueMap();
+        $map->setInfo(null);
+
+        $this->assertTrue(true);
+    }
+
+
     /**
      * @expectedException \RuntimeException
      * @expectedExceptionMessage WeakValueMap expects data to be object, NULL given
@@ -173,6 +182,12 @@ public function testSetInfoWithNoCurrent()
     public function testSetInfoNotObject()
     {
         $map = new WeakValueMap();
+
+        $obj1 = new stdClass();
+        $inf1 = new stdClass();
+        $map->attach($obj1, $inf1);
+
+        $map->rewind();
         $map->setInfo(null);
     }