diff --git a/blockcache_alter.module b/blockcache_alter.module
index f9cb113..ec42eb6 100644
--- a/blockcache_alter.module
+++ b/blockcache_alter.module
@@ -131,8 +131,9 @@ function blockcache_alter_block_view_alter(&$data, $block) {
     // This can only apply to blocks that are render arrays.
     if (isset($data['content']) && is_array($data['content'])) {
       $blockcache_alter = blockcache_alter_load_cache_configurations();
-      if (isset($blockcache_alter[$block->bid])) {
-        $block->cache = $blockcache_alter[$block->bid]->cache;
+      $fake_bid = $block->module . '-' . $block->delta . '-' . $block->theme;
+      if (isset($blockcache_alter[$fake_bid])) {
+        $block->cache = $blockcache_alter[$fake_bid]->cache;
       }
 
       // Set the block render array to cache based on our settings.
@@ -157,14 +158,17 @@ function blockcache_alter_load_cache_configurations() {
   $blockcache_alter = &drupal_static(__FUNCTION__, FALSE);
 
   if ($blockcache_alter === FALSE) {
-    $results = db_select('blockcache_alter', 'b')
-      ->fields('b')
-      ->execute()
+    $blockcache_alter = array();
+    $results = db_select('blockcache_alter', 'bca')
+      ->fields('bca');
+    $results->join('block', 'b', 'bca.bid = %alias.bid');
+    $results->fields('b', array('theme'));
+    $results = $results->execute()
       ->fetchAll();
 
-    $blockcache_alter = array();
     foreach ($results as $block) {
-      $blockcache_alter[$block->module . '-' . $block->delta] = $block;
+      $fake_bid = $block->module . '-' . $block->delta . '-' . $block->theme;
+      $blockcache_alter[$fake_bid] = $block;
     }
   }