Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -360,10 +360,13 @@
 		size_max="(~(size_t)0)"
 	])
 	AC_DEFINE_UNQUOTED(SIZE_MAX, $size_max, [Maximum value for size_t])
 ])
 
+AC_CHECK_TYPE(max_align_t,
+	[AC_DEFINE(OF_HAVE_MAX_ALIGN_T, 1, [Whether we have max_align_t])])
+
 AC_CHECK_SIZEOF(float)
 AC_CHECK_SIZEOF(double)
 AS_IF([test x"$ac_cv_sizeof_float" != x"4" -o x"$ac_cv_sizeof_double" != x"8"],
 	[AC_MSG_ERROR(
 		[Floating point implementation does not conform to IEEE 754!])])

Index: src/OFObject.m
==================================================================
--- src/OFObject.m
+++ src/OFObject.m
@@ -81,15 +81,15 @@
 	struct pre_mem *prev, *next;
 	id owner;
 };
 
 #define PRE_IVARS_ALIGN ((sizeof(struct pre_ivar) + \
-	(__BIGGEST_ALIGNMENT__ - 1)) & ~(__BIGGEST_ALIGNMENT__ - 1))
+	(OF_BIGGEST_ALIGNMENT - 1)) & ~(OF_BIGGEST_ALIGNMENT - 1))
 #define PRE_IVARS ((struct pre_ivar*)(void*)((char*)self - PRE_IVARS_ALIGN))
 
 #define PRE_MEM_ALIGN ((sizeof(struct pre_mem) + \
-	(__BIGGEST_ALIGNMENT__ - 1)) & ~(__BIGGEST_ALIGNMENT__ - 1))
+	(OF_BIGGEST_ALIGNMENT - 1)) & ~(OF_BIGGEST_ALIGNMENT - 1))
 #define PRE_MEM(mem) ((struct pre_mem*)(void*)((char*)mem - PRE_MEM_ALIGN))
 
 static struct {
 	Class isa;
 } allocFailedException;

Index: src/macros.h
==================================================================
--- src/macros.h
+++ src/macros.h
@@ -51,13 +51,19 @@
 # define OF_BYTE_ORDER_NATIVE OF_BYTE_ORDER_BIG_ENDIAN
 #else
 # define OF_BYTE_ORDER_NATIVE OF_BYTE_ORDER_LITTLE_ENDIAN
 #endif
 
-/* Hopefully no arch needs more than 16 bytes padding */
-#ifndef __BIGGEST_ALIGNMENT__
-# define __BIGGEST_ALIGNMENT__ 16
+#if __STDC_VERSION__ >= 201112L && defined(OF_HAVE_MAX_ALIGN_T)
+# define OF_BIGGEST_ALIGNMENT _Alignof(max_align_t)
+#else
+# ifdef __BIGGEST_ALIGNMENT__
+#  define OF_BIGGEST_ALIGNMENT __BIGGEST_ALIGNMENT__
+# else
+#  /* Hopefully no arch needs more than 16 bytes padding */
+#  define OF_BIGGEST_ALIGNMENT 16
+# endif
 #endif
 
 #ifdef __GNUC__
 # if defined(__amd64__) || defined(__x86_64__)
 #  define OF_AMD64_ASM

Index: src/objfw-defs.h.in
==================================================================
--- src/objfw-defs.h.in
+++ src/objfw-defs.h.in
@@ -7,10 +7,11 @@
 #undef OF_HAVE_CHOWN
 #undef OF_HAVE_COMPILER_TLS
 #undef OF_HAVE_FORWARDING_TARGET_FOR_SELECTOR
 #undef OF_HAVE_GCC_ATOMIC_OPS
 #undef OF_HAVE_LINK
+#undef OF_HAVE_MAX_ALIGN_T
 #undef OF_HAVE_OSATOMIC
 #undef OF_HAVE_OSATOMIC_64
 #undef OF_HAVE_PIPE
 #undef OF_HAVE_PLUGINS
 #undef OF_HAVE_PROCESSES