diff --git a/tests/helper.inc.php b/tests/helper.inc.php
index eebdf23..5075c67 100644
--- a/tests/helper.inc.php
+++ b/tests/helper.inc.php
@@ -15,7 +15,7 @@ class Test {
     }
 }
 
-function get_raw_image() {
+function create_png() {
     // PNG image data, 1 x 1, 1-bit colormap, non-interlaced
     ob_start();
     imagepng(imagecreatefromstring(base64_decode('R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7')));
@@ -23,3 +23,9 @@ function get_raw_image() {
     ob_end_clean();
     return $raw_image;
 }
+
+function get_png() {
+    $tmp_filename = tempnam('/tmp', 'php-curl-class.');
+    file_put_contents($tmp_filename, create_png());
+    return $tmp_filename;
+}
diff --git a/tests/run.php b/tests/run.php
index 1223fa4..35b7ea4 100644
--- a/tests/run.php
+++ b/tests/run.php
@@ -44,17 +44,16 @@ class CurlTest extends PHPUnit_Framework_TestCase {
     }
 
     public function testPostFilePathUpload() {
-        $tmp_filename = tempnam('/tmp', 'php-curl-class.');
-        file_put_contents($tmp_filename, get_raw_image());
+        $file_path = get_png();
 
         $test = new Test();
         $this->assertTrue($test->server('POST', array(
             'test' => 'post_file_path_upload',
             'key' => 'image',
-            'image' => '@' . $tmp_filename,
+            'image' => '@' . $file_path,
         )) === 'image/png');
 
-        unlink($tmp_filename);
+        unlink($file_path);
     }
 
     public function testPutRequestMethod() {