diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index dad6f65..fc6d7a8 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -537,12 +537,15 @@ function _theme($hook, $variables = array()) {
 
   // If an array of hook candidates were passed, use the first one that has an
   // implementation.
+  $original_suggestions = array();
   if (is_array($hook)) {
     foreach ($hook as $candidate) {
       if ($theme_registry->has($candidate)) {
         break;
       }
     }
+    // Store the passed in hooks as theme hook suggestions.
+    $original_suggestions = $hook;
     $hook = $candidate;
   }
   // Save the original theme hook, so it can be supplied to theme variable
@@ -637,6 +640,7 @@ function _theme($hook, $variables = array()) {
   if (isset($info['base hook'])) {
     $suggestions[] = $hook;
   }
+  $suggestions = array_merge($suggestions, $original_suggestions);
 
   // Invoke hook_theme_suggestions_alter() and
   // hook_theme_suggestions_HOOK_alter().
@@ -657,6 +661,9 @@ function _theme($hook, $variables = array()) {
       break;
     }
   }
+  // Add the suggestions to the $info array so that preprocess callbacks can
+  // act on that information.
+  $info['suggestions'] = $suggestions;
 
   // Invoke the variable preprocessors, if any.
   if (isset($info['base hook'])) {