diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh
index 1f1e9a49f59a..4a5f031be232 100755
--- a/tools/testing/selftests/net/pmtu.sh
+++ b/tools/testing/selftests/net/pmtu.sh
@@ -1348,7 +1348,7 @@ test_pmtu_ipvX_over_bridged_vxlanY_or_geneveY_exception() {
 
 		sleep 1
 
-		dd if=/dev/zero of=/dev/stdout status=none bs=1M count=1 | ${target} socat -T 3 -u STDIN $TCPDST,connect-timeout=3
+		dd if=/dev/zero status=none bs=1M count=1 | ${target} socat -T 3 -u STDIN $TCPDST,connect-timeout=3
 
 		size=$(du -sb $tmpoutfile)
 		size=${size%%/tmp/*}