diff --git a/config-templates/config.php b/config-templates/config.php
index f25f30b1e955ba0c01dd60ddf21254cb4f444aa0..0fafbdc7c9ca8f5d8395ffc5935974478fc68a20 100644
--- a/config-templates/config.php
+++ b/config-templates/config.php
@@ -608,7 +608,7 @@ $config = array(
      * than one instance is using memcache, you probably want to assign
      * a unique value per instance to this setting to avoid data collision.
      */
-    'memcache_store.prefix' => null,
+    'memcache_store.prefix' => '',
 
     /*
      * This value is the duration data should be stored in memcache. Data