diff --git a/solr/configsets/sunspot/conf/solrconfig.xml b/solr/configsets/sunspot/conf/solrconfig.xml
index 3b7a581d58..85963ed86b 100644
--- a/solr/configsets/sunspot/conf/solrconfig.xml
+++ b/solr/configsets/sunspot/conf/solrconfig.xml
@@ -544,7 +544,7 @@
       <!-- change field to textSpell and use copyField in schema.xml
       to spellcheck multiple fields -->
       <str name="field">textSpell</str>
-      <str name="buildOnCommit">true</str>
+      <str name="buildOnOptimize">true</str>
     </lst>
 
     <lst name="spellchecker">