diff --git a/data.php b/data.php
index 78646b0..535345c 100644
--- a/data.php
+++ b/data.php
@@ -64,11 +64,21 @@ class Data extends Base {
     }
 
     public function getMimeType () {
+        $result = "application/octet-stream";
         if ($this->isKnownType ()) {
             return self::$mimetypes [$this->extension];
-        } else {
-            return "application/octet-stream";
+        } elseif (function_exists('finfo_open') === true) {
+            $finfo = finfo_open(FILEINFO_MIME_TYPE);
+
+            if (is_resource($finfo) === true)
+            {
+                $result = finfo_file($finfo, $this->getLocalPath ());
+            }
+
+            finfo_close($finfo);
+            
         }
+        return $result;
     }
 
     public function getFilename () {
diff --git a/test/bookTest.php b/test/bookTest.php
index a2fac8f..88e3b59 100644
--- a/test/bookTest.php
+++ b/test/bookTest.php
@@ -291,6 +291,29 @@ class BookTest extends PHPUnit_Framework_TestCase
 
         $this->assertNull ($book->getDataFormat ("FB2"));
     }
+    
+    public function testGetMimeType  () {
+        $book = Book::getBookById(17);
+
+        // Get Alice MOBI=>17, PDF=>19, EPUB=>20
+        $data = $book->getDataFormat ("EPUB");
+        $this->assertEquals ("application/epub+zip", $data->getMimeType ());
+        $data = $book->getDataFormat ("MOBI");
+        $this->assertEquals ("application/x-mobipocket-ebook", $data->getMimeType ());
+        $data = $book->getDataFormat ("PDF");
+        $this->assertEquals ("application/pdf", $data->getMimeType ());
+        
+        // Alter a data to make a test for finfo_file if enabled 
+        $data->extension = "ico";
+        $data->format = "ICO";
+        $data->name = "favicon";
+        $data->book->path = realpath (dirname(__FILE__) . "/../");
+        if (function_exists('finfo_open') === true) {
+            $this->assertEquals ("image/x-icon", $data->getMimeType ());
+        } else {
+            $this->assertEquals ("application/octet-stream", $data->getMimeType ());
+        }
+    }
 
     public function testTypeaheadSearch ()
     {