diff --git a/modules/image/image.test b/modules/image/image.test
index 87d803a..8c327d5 100644
--- a/modules/image/image.test
+++ b/modules/image/image.test
@@ -1094,6 +1094,7 @@ class ImageFieldDisplayTestCase extends ImageFieldTestCase {
     // Add a default image to the public imagefield instance.
     $images = $this->drupalGetTestFiles('image');
     $edit = array(
+      // Get the path of the 'image-test.png' file.
       'files[field_settings_default_image]' => drupal_realpath($images[0]->uri),
     );
     $this->drupalPost('admin/structure/types/manage/article/fields/' . $field_name, $edit, t('Save settings'));
@@ -1107,8 +1108,8 @@ class ImageFieldDisplayTestCase extends ImageFieldTestCase {
     $this->assertRaw($default_output, 'Default image displayed when no user supplied image is present.');
 
     // Create a node with an image attached and ensure that the default image
-    // is not displayed.
-    $nid = $this->uploadNodeImage($images[1], $field_name, 'article');
+    // is not displayed. Upload the 'image-test.gif' file.
+    $nid = $this->uploadNodeImage($images[2], $field_name, 'article');
     $node = node_load($nid, NULL, TRUE);
     $image_info = array(
       'path' => $node->{$field_name}[LANGUAGE_NONE][0]['uri'],
@@ -1135,7 +1136,8 @@ class ImageFieldDisplayTestCase extends ImageFieldTestCase {
     $this->createImageField($private_field_name, 'article', array('uri_scheme' => 'private'));
     // Add a default image to the new field.
     $edit = array(
-      'files[field_settings_default_image]' => drupal_realpath($images[1]->uri),
+      // Get the path of the 'image-test.gif' file.
+      'files[field_settings_default_image]' => drupal_realpath($images[2]->uri),
     );
     $this->drupalPost('admin/structure/types/manage/article/fields/' . $private_field_name, $edit, t('Save settings'));
     $private_field = field_info_field($private_field_name);
diff --git a/modules/simpletest/tests/image.test b/modules/simpletest/tests/image.test
index ac4d3cf..3b98240 100644
--- a/modules/simpletest/tests/image.test
+++ b/modules/simpletest/tests/image.test
@@ -514,9 +514,9 @@ class ImageToolkitGdTestCase extends DrupalWebTestCase {
     $image->resource = imagecreatetruecolor(50, 20);
     $image->info['extension'] = 'gif';
     $image->toolkit = 'gd';
-    $resource = image_gd_create_tmp($image, 50, 20);
-    $color_index = imagecolorat($resource, 49, 0);
-    $color = array_values(imagecolorsforindex($resource, $color_index));
+    $image->resource = image_gd_create_tmp($image, 50, 20);
+    $color_index = imagecolorat($image->resource, 49, 0);
+    $color = array_values(imagecolorsforindex($image->resource, $color_index));
     $this->assertEqual($this->rotateTransparent, $color, "New GIF image with no transparent color set after creation has full transparent color at corner 1.");
     // Save image.
     $this->assertTrue(image_save($image, $file_path), format_string('New GIF image %file was saved.', array('%file' => $file)));