diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c
index 5bae1792e3d6372570e60c733506c2df9ea0ab50..104c75a33882c9538af0e0c61ecd92a81f4fdba6 100644
--- a/tools/testing/selftests/pidfd/pidfd_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_test.c
@@ -16,6 +16,10 @@
 
 #include "../kselftest.h"
 
+#ifndef __NR_pidfd_send_signal
+#define __NR_pidfd_send_signal -1
+#endif
+
 static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
 					unsigned int flags)
 {