diff --git a/test/nvmf/common.sh b/test/nvmf/common.sh
index 033d84990..397815dfb 100644
--- a/test/nvmf/common.sh
+++ b/test/nvmf/common.sh
@@ -101,7 +101,7 @@ function allocate_nic_ips() {
 	((count = NVMF_IP_LEAST_ADDR))
 	for nic_name in $(get_rdma_if_list); do
 		ip="$(get_ip_address $nic_name)"
-		if [ -z $ip ]; then
+		if [[ -z $ip ]]; then
 			ip addr add $NVMF_IP_PREFIX.$count/24 dev $nic_name
 			ip link set $nic_name up
 			((count = count + 1))