diff --git a/tools/build/envDefaults b/tools/build/envDefaults
index 473095c..cbc6577 100644
--- a/tools/build/envDefaults
+++ b/tools/build/envDefaults
@@ -9,10 +9,14 @@
 export KARAF_TAR=${KARAF_TAR:-~/Downloads/apache-karaf-3.0.1.tar.gz}
 export KARAF_DIST=$(basename $KARAF_ZIP .zip)
 
+# Fallback build number us derived from from the user name & time
+export BUILD_NUMBER=${BUILD_NUMBER:-$(id -un)~$(date +'%Y/%m/%d@%H:%M')}
+
 # ONOS Version and onos.tar.gz staging environment
-export ONOS_VERSION=${ONOS_VERSION:-1.0.0-SNAPSHOT}
+export ONOS_POM_VERSION="1.0.0-SNAPSHOT"
+export ONOS_VERSION=${ONOS_VERSION:-1.0.0.$BUILD_NUMBER}
+export ONOS_BITS=onos-${ONOS_VERSION%~*}
 export ONOS_STAGE_ROOT=${ONOS_STAGE_ROOT:-/tmp}
-export ONOS_BITS=onos-$ONOS_VERSION
 export ONOS_STAGE=$ONOS_STAGE_ROOT/$ONOS_BITS
 export ONOS_TAR=$ONOS_STAGE.tar.gz