diff --git a/src/fuzz/fuzz-dhcp6-client.c b/src/fuzz/fuzz-dhcp6-client.c
index 0417062c5f..c9bc2b3815 100644
--- a/src/fuzz/fuzz-dhcp6-client.c
+++ b/src/fuzz/fuzz-dhcp6-client.c
@@ -10,7 +10,7 @@
 #include "fd-util.h"
 #include "fuzz.h"
 
-static int test_dhcp_fd[2];
+static int test_dhcp_fd[2] = { -1, -1 };
 
 int dhcp6_network_send_udp_socket(int s, struct in6_addr *server_address,
                                   const void *packet, size_t len) {
diff --git a/src/fuzz/fuzz-ndisc-rs.c b/src/fuzz/fuzz-ndisc-rs.c
index 9c017acdeb..389b545ac2 100644
--- a/src/fuzz/fuzz-ndisc-rs.c
+++ b/src/fuzz/fuzz-ndisc-rs.c
@@ -10,7 +10,7 @@
 #include "socket-util.h"
 #include "ndisc-internal.h"
 
-static int test_fd[2];
+static int test_fd[2] = { -1, -1 };
 
 int icmp6_bind_router_solicitation(int index) {
         assert_se(socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0, test_fd) >= 0);