diff -uNr a/heartbeat/iSCSILogicalUnit b/heartbeat/iSCSILogicalUnit
--- a/heartbeat/iSCSILogicalUnit	2017-03-21 11:02:41.525216214 +0100
+++ b/heartbeat/iSCSILogicalUnit	2017-03-21 11:15:58.307410228 +0100
@@ -74,6 +74,8 @@
 # OCF_RESKEY_tgt_bsoflags
 # OCF_RESKEY_tgt_device_type
 
+# targetcli: iSCSITarget and iSCSILogicalUnit must use the same lockfile
+TARGETLOCKFILE=${HA_RSCTMP}/targetcli.lock
 #######################################################################
 
 meta_data() {
@@ -360,6 +362,8 @@
 		fi
 		;;
 	lio-t)
+		ocf_take_lock $TARGETLOCKFILE
+		ocf_release_lock_on_exit $TARGETLOCKFILE
 		# For lio, we first have to create a target device, then
 		# add it to the Target Portal Group as an LU.
 		ocf_run targetcli /backstores/block create name=${OCF_RESOURCE_INSTANCE} dev=${OCF_RESKEY_path} || exit $OCF_ERR_GENERIC
@@ -434,6 +438,8 @@
 		fi
 		;;
 	lio-t)
+		ocf_take_lock $TARGETLOCKFILE
+		ocf_release_lock_on_exit $TARGETLOCKFILE
 		ocf_run targetcli /iscsi/${OCF_RESKEY_target_iqn}/tpg1/luns delete ${OCF_RESKEY_lun} || exit $OCF_ERR_GENERIC
 		if [ -n "${OCF_RESKEY_allowed_initiators}" ]; then
 			for initiator in ${OCF_RESKEY_allowed_initiators}; do
diff -uNr a/heartbeat/iSCSITarget b/heartbeat/iSCSITarget
--- a/heartbeat/iSCSITarget	2017-03-21 11:02:41.506216405 +0100
+++ b/heartbeat/iSCSITarget	2017-03-21 11:19:13.493453664 +0100
@@ -50,6 +50,9 @@
 
 # Lockfile, used for selecting a target ID
 LOCKFILE=${HA_RSCTMP}/iSCSITarget-${OCF_RESKEY_implementation}.lock
+
+# targetcli: iSCSITarget and iSCSILogicalUnit must use the same lockfile
+TARGETLOCKFILE=${HA_RSCTMP}/targetcli.lock
 #######################################################################
 
 meta_data() {
@@ -325,6 +328,8 @@
 		# number 1. In lio, creating a network portal
 		# automatically creates the corresponding target if it
 		# doesn't already exist.
+		ocf_take_lock $TARGETLOCKFILE
+		ocf_release_lock_on_exit $TARGETLOCKFILE
 		for portal in ${OCF_RESKEY_portals}; do
 			if [ $portal != ${OCF_RESKEY_portals_default} ] ; then
 				ocf_run targetcli /iscsi set global auto_add_default_portal=false || exit $OCF_ERR_GENERIC
@@ -479,6 +484,8 @@
 		ocf_run lio_node --deliqn ${OCF_RESKEY_iqn} || exit $OCF_ERR_GENERIC
 		;;
 	lio-t)
+		ocf_take_lock $TARGETLOCKFILE
+		ocf_release_lock_on_exit $TARGETLOCKFILE
 		ocf_run targetcli /iscsi delete ${OCF_RESKEY_iqn} || exit $OCF_ERR_GENERIC
 		;;
 	esac