--- /dev/null
+ src/fcatomic.h | 12 ++----------
+ 1 file changed, 2 insertions(+), 10 deletions(-)
+
+diff --git a/src/fcatomic.h b/src/fcatomic.h
+index cc28a883c13fadf2ad9900586a9cae3097354671..657a5f551adfc37415231b7002746ad6cd031c78 100644
+--- a/src/fcatomic.h
++++ b/src/fcatomic.h
+@@ -70,24 +70,16 @@ typedef LONG fc_atomic_int_t;
+ #elif !defined(FC_NO_MT) && defined(__APPLE__)
+
+ #include <libkern/OSAtomic.h>
+-#ifdef __MAC_OS_X_MIN_REQUIRED
+ #include <AvailabilityMacros.h>
+-#elif defined(__IPHONE_OS_MIN_REQUIRED)
+-#include <Availability.h>
+-#endif
+
+ typedef int fc_atomic_int_t;
+ #define fc_atomic_int_add(AI, V) (OSAtomicAdd32Barrier ((V), &(AI)) - (V))
+
+ #define fc_atomic_ptr_get(P) (OSMemoryBarrier (), (void *) *(P))
+-#if (MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4 || __IPHONE_VERSION_MIN_REQUIRED >= 20100)
++#if (MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4 || __IPHONE_OS_VERSION_MIN_REQUIRED >= 20100)
+ #define fc_atomic_ptr_cmpexch(P,O,N) OSAtomicCompareAndSwapPtrBarrier ((void *) (O), (void *) (N), (void **) (P))
+ #else
+-#if __ppc64__ || __x86_64__
+-#define fc_atomic_ptr_cmpexch(P,O,N) OSAtomicCompareAndSwap64Barrier ((int64_t) (O), (int64_t) (N), (int64_t*) (P))
+-#else
+-#define fc_atomic_ptr_cmpexch(P,O,N) OSAtomicCompareAndSwap32Barrier ((int32_t) (O), (int32_t) (N), (int32_t*) (P))
+-#endif
++#error "Your macOS / iOS targets are too old"
+ #endif
+
+ #elif !defined(FC_NO_MT) && defined(HAVE_INTEL_ATOMIC_PRIMITIVES)