diff --git a/CRM/Contact/Form/DedupeRules.php b/CRM/Contact/Form/DedupeRules.php
index 3e8e1e70de01..beef61afbf9c 100644
--- a/CRM/Contact/Form/DedupeRules.php
+++ b/CRM/Contact/Form/DedupeRules.php
@@ -298,7 +298,7 @@ public function postProcess() {
 
     //need to clear cache of deduped contacts
     //based on the previous rule
-    $cacheKey = "merge {$this->_contactType}_{$this->_rgid}_%";
+    $cacheKey = "merge_{$this->_contactType}_{$this->_rgid}_%";
 
     CRM_Core_BAO_PrevNextCache::deleteItem(NULL, $cacheKey);