diff --git a/include/wx/platform.h b/include/wx/platform.h
index 7572c84162..c2449a2a57 100644
--- a/include/wx/platform.h
+++ b/include/wx/platform.h
@@ -415,6 +415,7 @@
 #ifdef __WXOSX__
 /* setup precise defines according to sdk used */
 #   include <TargetConditionals.h>
+#   include <Availability.h>
 #   if defined(__WXOSX_IPHONE__)
 #       if !( defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE )
 #           error "incorrect SDK for an iPhone build"