diff --git a/memcache.inc b/memcache.inc
index da2f8be..97af245 100644
--- a/memcache.inc
+++ b/memcache.inc
@@ -398,7 +398,7 @@ class MemCacheDrupal implements DrupalCacheInterface {
       ->execute();
     // If the variables are cached, get a fresh copy, update with the new value
     // and set it again.
-    if ($cached = cache_get('variables', 'cache_bootstrap')) {
+    if ($cached = cache_get('variables', 'cache_bootstrap') && !empty($cached->data)) {
       $variables = $cached->data;
       $variables[$name] = $value;
       cache_set('variables', $variables, 'cache_bootstrap');