diff --git a/facetapi.block.inc b/facetapi.block.inc
index 21b11bf..c0845cf 100644
--- a/facetapi.block.inc
+++ b/facetapi.block.inc
@@ -195,11 +195,13 @@ function facetapi_check_block_visibility($delta) {
 function facetapi_get_delta_map() {
   $map = &drupal_static(__FUNCTION__);
   if (NULL === $map) {
-    if ($data = cache_get('facetapi:delta_map') && !empty($data->data)) {
+    if ($data = cache_get('facetapi:delta_map')) {
       $map = $data->data;
     }
     else {
 
+      $map = array();
+
       // Maps deltas for all realms. This is a hack since not all realms display
       // facets in blocks, but it doesn't hurt to store the extra data. The map
       // is cached anyways, so it shouldn't cause too much additional resource