diff --git a/includes/theme.inc b/includes/theme.inc
index 67cbe85..fe99797 100644
--- a/includes/theme.inc
+++ b/includes/theme.inc
@@ -279,21 +279,7 @@ function _theme_registry_callback($callback = NULL, array $arguments = array())
  *   The name of the theme engine.
  */
 function _theme_load_registry($theme, $base_theme = NULL, $theme_engine = NULL) {
-  // Check the theme registry cache; if it exists, use it.
-  $cache = cache_get("theme_registry:$theme->name", 'cache');
-  if (isset($cache->data)) {
-    $registry = $cache->data;
-  }
-  else {
-    // If not, build one and cache it.
-    $registry = _theme_build_registry($theme, $base_theme, $theme_engine);
-   // Only persist this registry if all modules are loaded. This assures a
-   // complete set of theme hooks.
-    if (module_load_all(NULL)) {
-      _theme_save_registry($theme, $registry);
-    }
-  }
-  return $registry;
+  return new ThemeRegistry($theme, $base_theme, $theme_engine);
 }
 
 /**
@@ -562,6 +548,53 @@ function _theme_build_registry($theme, $base_theme, $theme_engine) {
   return $cache;
 }
 
+class ThemeRegistry Implements ArrayAccess {
+  protected $registry = array();
+
+  function __construct($theme, $base_theme = NULL, $theme_engine = NULL) {
+    $this->theme = $theme;
+    $this->base_theme = $base_theme;
+    $this->theme_engine = $theme_engine;
+
+    if ($cached = cache_get("theme_registry:$theme->name", 'cache')) {
+      $this->registry = $cached->data;
+    }
+    else {
+      $this->registry = _theme_build_registry($theme, $base_theme, $theme_engine);
+      // Only persist this registry if all modules are loaded. This assures a
+      // complete set of theme hooks.
+      if (module_load_all(NULL)) {
+        _theme_save_registry($theme, $registry);
+      }
+    }
+  }
+
+  public function offsetExists($offset) {
+    return isset($this->registry[$offset]);
+  }
+
+  public function offsetGet($offset) {
+    if (isset($this->registry[$offset])) {
+      return $this->registry[$offset];
+    }
+    else {
+      return NULL;
+    }
+  }
+
+  public function offsetSet($offset, $value) {
+    if (!isset($offset)) {
+      $this->registry[$offset] = $value;
+    }
+    else {
+      $this->registry[] = $value;
+    }
+  }
+  public function offsetUnset($offset) {
+    unset($this->registry[$offset]);
+  }
+}
+
 /**
  * Return a list of all currently available themes.
  *