diff --git a/modules/image/image.test b/modules/image/image.test
index e4b6d37..0320f3e 100644
--- a/modules/image/image.test
+++ b/modules/image/image.test
@@ -243,7 +243,7 @@ class ImageEffectsUnitTest extends ImageToolkitTestCase {
   }
 
   function setUp() {
-    parent::setUp('image_test');
+    parent::setUp('image_test', 'image_module_test');
     module_load_include('inc', 'image', 'image.effects');
   }
 
@@ -330,6 +330,25 @@ class ImageEffectsUnitTest extends ImageToolkitTestCase {
     $this->assertEqual($calls['rotate'][0][1], 90, t('Degrees were passed correctly'));
     $this->assertEqual($calls['rotate'][0][2], 0xffffff, t('Background color was passed correctly'));
   }
+
+  /**
+   * Test image effect caching.
+   */
+  function testImageEffectsCaching() {
+    $image_effect_definitions_called = &drupal_static('image_module_test_image_effect_info_alter');
+
+    // First call should grab a fresh copy of the data.
+    $effects = image_effect_definitions();
+    $this->assertTrue($image_effect_definitions_called === 1, 'image_effect_definitions() generated data.');
+
+    // Second call should come from cache.
+    drupal_static_reset('image_effect_definitions');
+    drupal_static_reset('image_module_test_image_effect_info_alter');
+    $cached_effects = image_effect_definitions();
+    $this->assertTrue(is_null($image_effect_definitions_called), 'image_effect_definitions() returned data from cache.');
+
+    $this->assertTrue($effects == $cached_effects, 'Cached effects are the same as generated effects.');
+  }
 }
 
 /**
diff --git a/modules/image/tests/image_module_test.module b/modules/image/tests/image_module_test.module
index 766a9d9..bb76cfb 100644
--- a/modules/image/tests/image_module_test.module
+++ b/modules/image/tests/image_module_test.module
@@ -39,3 +39,13 @@ function image_module_test_image_effect_info() {
 function image_module_test_null_effect(array &$image, array $data) {
   return TRUE;
 }
+
+/**
+ * Implements hook_image_effect_info_alter().
+ *
+ * Used to keep a count of cache misses in image_effect_definitions().
+ */
+function image_module_test_image_effect_info_alter(&$effects) {
+  $image_effects_definition_called = &drupal_static(__FUNCTION__, 0);
+  $image_effects_definition_called++;
+}