diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index a4252e000428..737a952dcf80 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -788,12 +788,13 @@ static const char *pkt_type_str(u16 pkt_type)
 	return "Unknown";
 }
 
+#define MAX_FLAGS_STRLEN 21
 /* Show the information of the transport layer in the packet */
 static void show_transport(const u_char *packet, u16 len, u32 ifindex,
 			   const char *src_addr, const char *dst_addr,
 			   u16 proto, bool ipv6, u8 pkt_type)
 {
-	char *ifname, _ifname[IF_NAMESIZE];
+	char *ifname, _ifname[IF_NAMESIZE], flags[MAX_FLAGS_STRLEN] = "";
 	const char *transport_str;
 	u16 src_port, dst_port;
 	struct udphdr *udp;
@@ -834,29 +835,21 @@ static void show_transport(const u_char *packet, u16 len, u32 ifindex,
 
 	/* TCP or UDP*/
 
-	flockfile(stdout);
+	if (proto == IPPROTO_TCP)
+		snprintf(flags, MAX_FLAGS_STRLEN, "%s%s%s%s",
+			 tcp->fin ? ", FIN" : "",
+			 tcp->syn ? ", SYN" : "",
+			 tcp->rst ? ", RST" : "",
+			 tcp->ack ? ", ACK" : "");
+
 	if (ipv6)
-		printf("%-7s %-3s IPv6 %s.%d > %s.%d: %s, length %d",
+		printf("%-7s %-3s IPv6 %s.%d > %s.%d: %s, length %d%s\n",
 		       ifname, pkt_type_str(pkt_type), src_addr, src_port,
-		       dst_addr, dst_port, transport_str, len);
+		       dst_addr, dst_port, transport_str, len, flags);
 	else
-		printf("%-7s %-3s IPv4 %s:%d > %s:%d: %s, length %d",
+		printf("%-7s %-3s IPv4 %s:%d > %s:%d: %s, length %d%s\n",
 		       ifname, pkt_type_str(pkt_type), src_addr, src_port,
-		       dst_addr, dst_port, transport_str, len);
-
-	if (proto == IPPROTO_TCP) {
-		if (tcp->fin)
-			printf(", FIN");
-		if (tcp->syn)
-			printf(", SYN");
-		if (tcp->rst)
-			printf(", RST");
-		if (tcp->ack)
-			printf(", ACK");
-	}
-
-	printf("\n");
-	funlockfile(stdout);
+		       dst_addr, dst_port, transport_str, len, flags);
 }
 
 static void show_ipv6_packet(const u_char *packet, u32 ifindex, u8 pkt_type)