diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh
index 04fcb8a077c995..e0615c6ffb8d1c 100755
--- a/tools/testing/selftests/net/mptcp/diag.sh
+++ b/tools/testing/selftests/net/mptcp/diag.sh
@@ -62,8 +62,8 @@ __chk_nr()
 	nr=$(eval $command)
 
 	printf "%-50s" "$msg"
-	if [ $nr != $expected ]; then
-		if [ $nr = "$skip" ] && ! mptcp_lib_expect_all_features; then
+	if [ "$nr" != "$expected" ]; then
+		if [ "$nr" = "$skip" ] && ! mptcp_lib_expect_all_features; then
 			echo "[ skip ] Feature probably not supported"
 			mptcp_lib_result_skip "${msg}"
 		else