diff --git a/src/base.h b/src/base.h
index 09f3133d..e5297745 100644
--- a/src/base.h
+++ b/src/base.h
@@ -158,6 +158,7 @@
 #endif
 
 #ifdef __APPLE__
+#include <AvailabilityMacros.h>
 #ifndef MAC_OS_X_VERSION_MIN_REQUIRED
 #define MAC_OS_X_VERSION_MIN_REQUIRED 1070 /* Mac OS X 10.7, 2011 */
 #endif