diff --git a/examples/nvme/arbitration/arbitration.c b/examples/nvme/arbitration/arbitration.c
index 3c63bd3f3..6afdfa9e8 100644
--- a/examples/nvme/arbitration/arbitration.c
+++ b/examples/nvme/arbitration/arbitration.c
@@ -457,7 +457,7 @@ usage(char *program_name)
 	printf("\t\n");
 	printf("\t[-d DPDK huge memory size in MB]\n");
 	printf("\t[-q io depth]\n");
-	printf("\t[-s io size in bytes]\n");
+	printf("\t[-o io size in bytes]\n");
 	printf("\t[-w io pattern type, must be one of\n");
 	printf("\t\t(read, write, randread, randwrite, rw, randrw)]\n");
 	printf("\t[-M rwmixread (100 for reads, 0 for writes)]\n");
@@ -641,7 +641,7 @@ parse_args(int argc, char **argv)
 	spdk_nvme_trid_populate_transport(&g_trid, SPDK_NVME_TRANSPORT_PCIE);
 	snprintf(g_trid.subnqn, sizeof(g_trid.subnqn), "%s", SPDK_NVMF_DISCOVERY_NQN);
 
-	while ((op = getopt(argc, argv, "a:b:c:d:ghi:l:m:n:q:r:s:t:w:M:L:")) != -1) {
+	while ((op = getopt(argc, argv, "a:b:c:d:ghi:l:m:n:o:q:r:t:w:M:L:")) != -1) {
 		switch (op) {
 		case 'c':
 			g_arbitration.core_mask = optarg;
@@ -699,7 +699,7 @@ parse_args(int argc, char **argv)
 			case 'q':
 				g_arbitration.queue_depth = val;
 				break;
-			case 's':
+			case 'o':
 				g_arbitration.io_size_bytes = val;
 				break;
 			case 't':
diff --git a/test/nvme/nvme.sh b/test/nvme/nvme.sh
index eda3a9025..b12a8c335 100755
--- a/test/nvme/nvme.sh
+++ b/test/nvme/nvme.sh
@@ -123,7 +123,7 @@ if [ $(uname) = Linux ]; then
 	start_stub "-s 4096 -i 0 -m 0xE"
 fi
 
-run_test "nvme_reset" $testdir/reset/reset -q 64 -w write -s 4096 -t 5
+run_test "nvme_reset" $testdir/reset/reset -q 64 -w write -o 4096 -t 5
 run_test "nvme_identify" nvme_identify
 run_test "nvme_perf" nvme_perf
 run_test "nvme_hello_world" $SPDK_EXAMPLE_DIR/hello_world -i 0
@@ -131,7 +131,7 @@ run_test "nvme_sgl" $testdir/sgl/sgl
 run_test "nvme_e2edp" $testdir/e2edp/nvme_dp
 run_test "nvme_reserve" $testdir/reserve/reserve
 run_test "nvme_err_injection" $testdir/err_injection/err_injection
-run_test "nvme_overhead" $testdir/overhead/overhead -s 4096 -t 1 -H -i 0
+run_test "nvme_overhead" $testdir/overhead/overhead -o 4096 -t 1 -H -i 0
 run_test "nvme_arbitration" $SPDK_EXAMPLE_DIR/arbitration -t 3 -i 0
 run_test "nvme_single_aen" $testdir/aer/aer -T -i 0 -L log
 
diff --git a/test/nvme/overhead/overhead.c b/test/nvme/overhead/overhead.c
index a2d9cbe2e..73c2694da 100644
--- a/test/nvme/overhead/overhead.c
+++ b/test/nvme/overhead/overhead.c
@@ -461,7 +461,7 @@ usage(char *program_name)
 #endif
 	printf("\t\n");
 	printf("\t[-d DPDK huge memory size in MB]\n");
-	printf("\t[-s io size in bytes]\n");
+	printf("\t[-o io size in bytes]\n");
 	printf("\t[-t time in seconds]\n");
 	printf("\t\t(default: 1)]\n");
 	printf("\t[-H enable histograms]\n");
@@ -540,13 +540,13 @@ parse_args(int argc, char **argv, struct spdk_env_opts *env_opts)
 	spdk_nvme_trid_populate_transport(&g_trid, SPDK_NVME_TRANSPORT_PCIE);
 	snprintf(g_trid.subnqn, sizeof(g_trid.subnqn), "%s", SPDK_NVMF_DISCOVERY_NQN);
 
-	while ((op = getopt(argc, argv, "d:ghi:r:s:t:HL:")) != -1) {
+	while ((op = getopt(argc, argv, "d:ghi:o:r:t:HL:")) != -1) {
 		switch (op) {
 		case 'h':
 			usage(argv[0]);
 			exit(0);
 			break;
-		case 's':
+		case 'o':
 			val = spdk_strtol(optarg, 10);
 			if (val < 0) {
 				fprintf(stderr, "Invalid io size\n");
diff --git a/test/nvme/reset/reset.c b/test/nvme/reset/reset.c
index f31e35a21..39eaba93c 100644
--- a/test/nvme/reset/reset.c
+++ b/test/nvme/reset/reset.c
@@ -293,7 +293,7 @@ usage(char *program_name)
 	printf("%s options", program_name);
 	printf("\n");
 	printf("\t[-q io depth]\n");
-	printf("\t[-s io size in bytes]\n");
+	printf("\t[-o io size in bytes]\n");
 	printf("\t[-w io pattern type, must be one of\n");
 	printf("\t\t(read, write, randread, randwrite, rw, randrw)]\n");
 	printf("\t[-M rwmixread (100 for reads, 0 for writes)]\n");
@@ -353,7 +353,7 @@ parse_args(int argc, char **argv)
 	g_time_in_sec = 0;
 	g_rw_percentage = -1;
 
-	while ((op = getopt(argc, argv, "q:s:t:w:M:")) != -1) {
+	while ((op = getopt(argc, argv, "o:q:t:w:M:")) != -1) {
 		if (op == 'w') {
 			workload_type = optarg;
 		} else if (op == '?') {
@@ -369,7 +369,7 @@ parse_args(int argc, char **argv)
 			case 'q':
 				g_queue_depth = val;
 				break;
-			case 's':
+			case 'o':
 				g_io_size_bytes = val;
 				break;
 			case 't':
diff --git a/test/nvmf/target/nvmf_vfio_user.sh b/test/nvmf/target/nvmf_vfio_user.sh
index 5b9ac6029..917174773 100755
--- a/test/nvmf/target/nvmf_vfio_user.sh
+++ b/test/nvmf/target/nvmf_vfio_user.sh
@@ -81,7 +81,7 @@ for i in $(seq 1 $NUM_DEVICES); do
 	sleep 1
 	$SPDK_EXAMPLE_DIR/hello_world -d 256 -g -r "trtype:$TEST_TRANSPORT traddr:$test_traddr subnqn:$test_subnqn"
 	sleep 1
-	$nvmeappdir/overhead/overhead -s 4096 -t 1 -H -g -d 256 -r "trtype:$TEST_TRANSPORT traddr:$test_traddr subnqn:$test_subnqn"
+	$nvmeappdir/overhead/overhead -o 4096 -t 1 -H -g -d 256 -r "trtype:$TEST_TRANSPORT traddr:$test_traddr subnqn:$test_subnqn"
 	sleep 1
 	aer_vfio_user $test_traddr $test_subnqn $i
 	sleep 1