diff --git a/lib/birdlib.h b/lib/birdlib.h
index 442bf600..bc7c334c 100644
--- a/lib/birdlib.h
+++ b/lib/birdlib.h
@@ -41,7 +41,7 @@
   size_t _alignment = _Alignof(typeof(*ptr)); \
   ptr = (typeof(ptr)) BIRD_ALIGN((uintptr_t)(val), _alignment); \
 } while (0)
-#define CPU_STRUCT_ALIGN  (MAX_(_Alignof(void*), _Alignof(u64)))
+#define CPU_STRUCT_ALIGN (alignof(max_align_t))
 #define BIRD_CPU_ALIGN(s) BIRD_ALIGN((s), CPU_STRUCT_ALIGN)
 
 /* Structure item alignment macros */
diff --git a/lib/mempool.c b/lib/mempool.c
index 1ca6d03b..b88bc122 100644
--- a/lib/mempool.c
+++ b/lib/mempool.c
@@ -28,8 +28,7 @@
 struct lp_chunk {
   struct lp_chunk *next;
   struct linpool *lp;
-  uintptr_t data_align[0];
-  _Atomic u64 data_align_atomic[0];
+  max_align_t data_align[0];
   byte data[0];
 };
 
diff --git a/lib/resource.c b/lib/resource.c
index 069e8c4d..8a923792 100644
--- a/lib/resource.c
+++ b/lib/resource.c
@@ -384,10 +384,7 @@ tmp_flush(void)
 struct mblock {
   resource r;
   unsigned size;
-  union {
-    uintptr_t bigint;
-    _Atomic u64 atom;
-  } _align[0];
+  max_align_t data_align[0];
   byte data[0];
 };
 
diff --git a/lib/slab.c b/lib/slab.c
index d68bfef1..9351a06d 100644
--- a/lib/slab.c
+++ b/lib/slab.c
@@ -68,7 +68,7 @@ static struct resclass sl_class = {
 
 struct sl_obj {
   node n;
-  uintptr_t data_align[0];
+  max_align_t data_align[0];
   byte data[0];
 };
 
@@ -168,13 +168,6 @@ struct sl_head {
   u32 used_bits[0];
 };
 
-struct sl_alignment {			/* Magic structure for testing of alignment */
-  byte data;
-  int x[0];
-  _Atomic u64 y[0];
-  void *z[0];
-};
-
 #define TLIST_PREFIX sl_head
 #define TLIST_TYPE   struct sl_head
 #define TLIST_ITEM   n
@@ -221,9 +214,7 @@ slab *
 sl_new(pool *p, uint size)
 {
   slab *s = ralloc(p, &sl_class);
-  uint align = sizeof(struct sl_alignment);
-  if (align < sizeof(void *))
-    align = sizeof(void *);
+  uint align = CPU_STRUCT_ALIGN;
   s->data_size = size;
   size = (size + align - 1) / align * align;
   s->obj_size = size;