diff --git a/Classes/PHPWord/Writer/Word2007.php b/Classes/PHPWord/Writer/Word2007.php
index 8375c56a..f58f2c43 100755
--- a/Classes/PHPWord/Writer/Word2007.php
+++ b/Classes/PHPWord/Writer/Word2007.php
@@ -25,6 +25,9 @@
  * @version    0.7.0
  */
 
+use PhpOffice\PhpWord\Exceptions\InvalidImageException;
+use PhpOffice\PhpWord\Exceptions\UnsupportedImageTypeException;
+
 /**
  * Class PHPWord_Writer_Word2007
  */
@@ -191,25 +194,40 @@ class PHPWord_Writer_Word2007 implements PHPWord_Writer_IWriter
         }
     }
 
-    private function _chkContentTypes($src)
+    /**
+     * @param string $src
+     */
+    private function checkContentTypes($src)
     {
-        $srcInfo = pathinfo($src);
-        $extension = strtolower($srcInfo['extension']);
-        if (substr($extension, 0, 3) == 'php') {
-            $extension = 'php';
-        }
-        $_supportedImageTypes = array('jpg', 'jpeg', 'gif', 'png', 'bmp', 'tif', 'tiff', 'php');
+        $supportedImageTypes = array(IMAGETYPE_JPEG, IMAGETYPE_GIF, IMAGETYPE_PNG, IMAGETYPE_BMP, IMAGETYPE_TIFF_II, IMAGETYPE_TIFF_MM);
 
-        if (in_array($extension, $_supportedImageTypes)) {
-            $imagedata = getimagesize($src);
-            $imagetype = image_type_to_mime_type($imagedata[2]);
-            $imageext = image_type_to_extension($imagedata[2]);
-            $imageext = str_replace('.', '', $imageext);
-            if ($imageext == 'jpeg') {
-                $imageext = 'jpg';
+        $extension = null;
+        if (stripos(strrev($src), strrev('.php')) === 0) {
+            $extension = 'php';
+        } else {
+            $imageType = exif_imagetype($src);
+            if ($imageType === IMAGETYPE_JPEG) {
+                $extension = 'jpg';
+            } elseif ($imageType === IMAGETYPE_GIF) {
+                $extension = 'gif';
+            } elseif ($imageType === IMAGETYPE_PNG) {
+                $extension = 'png';
+            } elseif ($imageType === IMAGETYPE_BMP) {
+                $extension = 'bmp';
+            } elseif ($imageType === IMAGETYPE_TIFF_II || $imageType === IMAGETYPE_TIFF_MM) {
+                $extension = 'tif';
             }
-            if (!in_array($imagetype, $this->_imageTypes)) {
-                $this->_imageTypes[$imageext] = $imagetype;
+        }
+
+        if (in_array($extension, $supportedImageTypes)) {
+            $imageData = getimagesize($src);
+            $imageType = image_type_to_mime_type($imageData[2]);
+            $imageExtension = str_replace('.', '', image_type_to_extension($imageData[2]));
+            if ($imageExtension === 'jpeg') {
+                $imageExtension = 'jpg';
+            }
+            if (!in_array($imageType, $this->_imageTypes)) {
+                $this->_imageTypes[$imageExtension] = $imageType;
             }
         } else {
             if (!in_array($extension, $this->_objectTypes)) {
@@ -258,10 +276,10 @@ class PHPWord_Writer_Word2007 implements PHPWord_Writer_IWriter
             $objZip->addFromString('word/' . $element['target'], $imageContents);
             imagedestroy($image);
 
-            $this->_chkContentTypes($element['source']);
+            $this->checkContentTypes($element['source']);
         } else {
             $objZip->addFile($element['source'], 'word/' . $element['target']);
-            $this->_chkContentTypes($element['source']);
+            $this->checkContentTypes($element['source']);
         }
     }
 }
diff --git a/Tests/PHPWord/Writer/Word2007Test.php b/Tests/PHPWord/Writer/Word2007Test.php
index 28b0d581..59bc6387 100644
--- a/Tests/PHPWord/Writer/Word2007Test.php
+++ b/Tests/PHPWord/Writer/Word2007Test.php
@@ -4,6 +4,7 @@ namespace PHPWord\Tests\Writer;
 use PHPUnit_Framework_TestCase;
 use PHPWord_Writer_Word2007;
 use PHPWord;
+use PHPWord\Tests\TestHelperDOCX;
 
 /**
  * Class Word2007Test
@@ -13,9 +14,11 @@ use PHPWord;
  */
 class Word2007Test extends \PHPUnit_Framework_TestCase
 {
-    /**
-     * Test construct
-     */
+    public function tearDown()
+    {
+        TestHelperDOCX::clear();
+    }
+
     public function testConstruct()
     {
         $object = new PHPWord_Writer_Word2007(new PHPWord());
@@ -35,9 +38,6 @@ class Word2007Test extends \PHPUnit_Framework_TestCase
         }
     }
 
-    /**
-     * Test save()
-     */
     public function testSave()
     {
         $phpWord = new PHPWord();
@@ -60,4 +60,29 @@ class Word2007Test extends \PHPUnit_Framework_TestCase
         $this->assertTrue(file_exists($file));
         unlink($file);
     }
-}
+
+    /**
+     * @covers PHPWord_Writer_Word2007::checkContentTypes
+     */
+    public function testCheckContentTypes()
+    {
+        $phpWord = new PHPWord();
+        $section = $phpWord->createSection();
+        $section->addImage(PHPWORD_TESTS_DIR_ROOT . "/_files/images/mars_noext_jpg");
+        $section->addImage(PHPWORD_TESTS_DIR_ROOT . "/_files/images/mars.jpg");
+        $section->addImage(PHPWORD_TESTS_DIR_ROOT . "/_files/images/mario.gif");
+        $section->addImage(PHPWORD_TESTS_DIR_ROOT . "/_files/images/firefox.png");
+        $section->addImage(PHPWORD_TESTS_DIR_ROOT . "/_files/images/duke_nukem.bmp");
+        $section->addImage(PHPWORD_TESTS_DIR_ROOT . "/_files/images/angela_merkel.tif");
+
+        $doc = TestHelperDOCX::getDocument($phpWord);
+        $mediaPath = $doc->getPath() . "/word/media";
+
+        $this->assertFileEquals(PHPWORD_TESTS_DIR_ROOT . "/_files/images/mars_noext_jpg", $mediaPath . "/section_image1.jpg");
+        $this->assertFileEquals(PHPWORD_TESTS_DIR_ROOT . "/_files/images/mars.jpg", $mediaPath . "/section_image2.jpg");
+        $this->assertFileEquals(PHPWORD_TESTS_DIR_ROOT . "/_files/images/mario.gif", $mediaPath . "/section_image3.gif");
+        $this->assertFileEquals(PHPWORD_TESTS_DIR_ROOT . "/_files/images/firefox.png", $mediaPath . "/section_image4.png");
+        $this->assertFileEquals(PHPWORD_TESTS_DIR_ROOT . "/_files/images/duke_nukem.bmp", $mediaPath . "/section_image5.bmp");
+        $this->assertFileEquals(PHPWORD_TESTS_DIR_ROOT . "/_files/images/angela_merkel.tif", $mediaPath . "/section_image6.tif");
+    }
+}
\ No newline at end of file
diff --git a/Tests/_inc/TestHelperDOCX.php b/Tests/_inc/TestHelperDOCX.php
index 643cc00a..a368b8e4 100644
--- a/Tests/_inc/TestHelperDOCX.php
+++ b/Tests/_inc/TestHelperDOCX.php
@@ -59,4 +59,4 @@ class TestHelperDOCX
 
         rmdir($dir);
     }
-}
+}
\ No newline at end of file
diff --git a/Tests/_inc/XmlDocument.php b/Tests/_inc/XmlDocument.php
index 69569aa6..f16bd6d8 100644
--- a/Tests/_inc/XmlDocument.php
+++ b/Tests/_inc/XmlDocument.php
@@ -63,4 +63,20 @@ class XmlDocument
         $elements = $this->xpath->query($path);
         return $elements->item(0);
     }
+
+    /**
+     * @return string
+     */
+    public function getFile()
+    {
+        return $this->file;
+    }
+
+    /**
+     * @return string
+     */
+    public function getPath()
+    {
+        return $this->path;
+    }
 }