diff --git a/gpAux/gpdemo/demo_cluster.sh b/gpAux/gpdemo/demo_cluster.sh
index 635f2dca3b225f3ae1cb071eae438567f1eae4b2..3e74e91cbe682769c26d5eb3b81034464b52b868 100755
--- a/gpAux/gpdemo/demo_cluster.sh
+++ b/gpAux/gpdemo/demo_cluster.sh
@@ -4,7 +4,7 @@
 # Data Directories
 # ======================================================================
 
-DATADIRS?=`pwd`/datadirs
+DATADIRS=${DATADIRS:-`pwd`/datadirs}
 QDDIR=$DATADIRS/qddir
 
 SEG_PREFIX=demoDataDir