diff --git a/tools/testing/selftests/vm/pkey-powerpc.h b/tools/testing/selftests/vm/pkey-powerpc.h
index e4aa597..1ebb586 100644
--- a/tools/testing/selftests/vm/pkey-powerpc.h
+++ b/tools/testing/selftests/vm/pkey-powerpc.h
@@ -32,7 +32,7 @@
 					     pkey-31 and exec-only key */
 #define PKEY_BITS_PER_PKEY	2
 #define HPAGE_SIZE		(1UL << 24)
-#define PAGE_SIZE		(1UL << 16)
+#define PAGE_SIZE		sysconf(_SC_PAGESIZE)
 
 static inline u32 pkey_bit_position(int pkey)
 {
diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index a1cb9a7..fc19add 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -146,7 +146,12 @@ void abort_hooks(void)
  * will then fault, which makes sure that the fault code handles
  * execute-only memory properly.
  */
+#ifdef __powerpc64__
+/* This way, both 4K and 64K alignment are maintained */
+__attribute__((__aligned__(65536)))
+#else
 __attribute__((__aligned__(PAGE_SIZE)))
+#endif
 void lots_o_noops_around_write(int *write_to_me)
 {
 	dprintf3("running %s()\n", __func__);