diff --git a/tools/testing/selftests/powerpc/benchmarks/null_syscall.c b/tools/testing/selftests/powerpc/benchmarks/null_syscall.c
index 579f0215c6e72325799030a6d392e2401f581edb..9836838a529f68681b3090ba6f9ddddcc853d15f 100644
--- a/tools/testing/selftests/powerpc/benchmarks/null_syscall.c
+++ b/tools/testing/selftests/powerpc/benchmarks/null_syscall.c
@@ -14,6 +14,7 @@
 #include <time.h>
 #include <sys/types.h>
 #include <sys/time.h>
+#include <sys/syscall.h>
 #include <signal.h>
 
 static volatile int soak_done;
@@ -121,7 +122,7 @@ static void do_null_syscall(unsigned long nr)
 	unsigned long i;
 
 	for (i = 0; i < nr; i++)
-		getppid();
+		syscall(__NR_gettid);
 }
 
 #define TIME(A, STR) \