diff --git a/tools/testing/selftests/powerpc/security/Makefile b/tools/testing/selftests/powerpc/security/Makefile
index d68e6031695c..eadbbff50be6 100644
--- a/tools/testing/selftests/powerpc/security/Makefile
+++ b/tools/testing/selftests/powerpc/security/Makefile
@@ -8,4 +8,6 @@ CFLAGS += -I../../../../../usr/include
 include ../../lib.mk
 
 $(TEST_GEN_PROGS): ../harness.c ../utils.c
+
+$(OUTPUT)/spectre_v2: CFLAGS += -m64
 $(OUTPUT)/spectre_v2: ../pmu/event.c branch_loops.S