diff --git a/src/c/_cffi_backend.c b/src/c/_cffi_backend.c
index 537271f..9c3bf94 100644
--- a/src/c/_cffi_backend.c
+++ b/src/c/_cffi_backend.c
@@ -103,11 +103,11 @@
 # define CFFI_CHECK_FFI_PREP_CIF_VAR 0
 # define CFFI_CHECK_FFI_PREP_CIF_VAR_MAYBE 0
 
-#elif defined(__APPLE__) && defined(FFI_AVAILABLE_APPLE)
+#elif defined(__APPLE__)
 
-# define CFFI_CHECK_FFI_CLOSURE_ALLOC __builtin_available(macos 10.15, ios 13, watchos 6, tvos 13, *)
+# define CFFI_CHECK_FFI_CLOSURE_ALLOC 1
 # define CFFI_CHECK_FFI_CLOSURE_ALLOC_MAYBE 1
-# define CFFI_CHECK_FFI_PREP_CLOSURE_LOC __builtin_available(macos 10.15, ios 13, watchos 6, tvos 13, *)
+# define CFFI_CHECK_FFI_PREP_CLOSURE_LOC 1
 # define CFFI_CHECK_FFI_PREP_CLOSURE_LOC_MAYBE 1
-# define CFFI_CHECK_FFI_PREP_CIF_VAR __builtin_available(macos 10.15, ios 13, watchos 6, tvos 13, *)
+# define CFFI_CHECK_FFI_PREP_CIF_VAR 1
 # define CFFI_CHECK_FFI_PREP_CIF_VAR_MAYBE 1
@@ -6422,7 +6422,7 @@ static PyObject *b_callback(PyObject *self, PyObject *args)
     else
 #endif
     {
-#if defined(__APPLE__) && defined(FFI_AVAILABLE_APPLE) && !FFI_LEGACY_CLOSURE_API
+#if defined(__APPLE__) && !FFI_LEGACY_CLOSURE_API
         PyErr_Format(PyExc_SystemError, "ffi_prep_closure_loc() is missing");
         goto error;
 #else