diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index b902ba249ad97e..73417bcbaf6e91 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -1252,13 +1252,13 @@ chk_csum_nr()
 
 	printf "%-${nr_blank}s %s" " " "sum"
 	count=$(get_counter ${ns1} "MPTcpExtDataCsumErr")
-	if [ "$count" != "$csum_ns1" ]; then
+	if [ -n "$count" ] && [ "$count" != "$csum_ns1" ]; then
 		extra_msg="$extra_msg ns1=$count"
 	fi
 	if [ -z "$count" ]; then
 		echo -n "[skip]"
 	elif { [ "$count" != $csum_ns1 ] && [ $allow_multi_errors_ns1 -eq 0 ]; } ||
-	   { [ "$count" -lt $csum_ns1 ] && [ $allow_multi_errors_ns1 -eq 1 ]; }; then
+	     { [ "$count" -lt $csum_ns1 ] && [ $allow_multi_errors_ns1 -eq 1 ]; }; then
 		echo "[fail] got $count data checksum error[s] expected $csum_ns1"
 		fail_test
 		dump_stats=1
@@ -1267,13 +1267,13 @@ chk_csum_nr()
 	fi
 	echo -n " - csum  "
 	count=$(get_counter ${ns2} "MPTcpExtDataCsumErr")
-	if [ "$count" != "$csum_ns2" ]; then
+	if [ -n "$count" ] && [ "$count" != "$csum_ns2" ]; then
 		extra_msg="$extra_msg ns2=$count"
 	fi
 	if [ -z "$count" ]; then
 		echo -n "[skip]"
 	elif { [ "$count" != $csum_ns2 ] && [ $allow_multi_errors_ns2 -eq 0 ]; } ||
-	   { [ "$count" -lt $csum_ns2 ] && [ $allow_multi_errors_ns2 -eq 1 ]; }; then
+	     { [ "$count" -lt $csum_ns2 ] && [ $allow_multi_errors_ns2 -eq 1 ]; }; then
 		echo "[fail] got $count data checksum error[s] expected $csum_ns2"
 		fail_test
 		dump_stats=1
@@ -1315,13 +1315,13 @@ chk_fail_nr()
 
 	printf "%-${nr_blank}s %s" " " "ftx"
 	count=$(get_counter ${ns_tx} "MPTcpExtMPFailTx")
-	if [ "$count" != "$fail_tx" ]; then
+	if [ -n "$count" ] && [ "$count" != "$fail_tx" ]; then
 		extra_msg="$extra_msg,tx=$count"
 	fi
 	if [ -z "$count" ]; then
 		echo -n "[skip]"
 	elif { [ "$count" != "$fail_tx" ] && [ $allow_tx_lost -eq 0 ]; } ||
-	   { [ "$count" -gt "$fail_tx" ] && [ $allow_tx_lost -eq 1 ]; }; then
+	     { [ "$count" -gt "$fail_tx" ] && [ $allow_tx_lost -eq 1 ]; }; then
 		echo "[fail] got $count MP_FAIL[s] TX expected $fail_tx"
 		fail_test
 		dump_stats=1
@@ -1331,13 +1331,13 @@ chk_fail_nr()
 
 	echo -n " - failrx"
 	count=$(get_counter ${ns_rx} "MPTcpExtMPFailRx")
-	if [ "$count" != "$fail_rx" ]; then
+	if [ -n "$count" ] && [ "$count" != "$fail_rx" ]; then
 		extra_msg="$extra_msg,rx=$count"
 	fi
 	if [ -z "$count" ]; then
 		echo -n "[skip]"
 	elif { [ "$count" != "$fail_rx" ] && [ $allow_rx_lost -eq 0 ]; } ||
-	   { [ "$count" -gt "$fail_rx" ] && [ $allow_rx_lost -eq 1 ]; }; then
+	     { [ "$count" -gt "$fail_rx" ] && [ $allow_rx_lost -eq 1 ]; }; then
 		echo "[fail] got $count MP_FAIL[s] RX expected $fail_rx"
 		fail_test
 		dump_stats=1