diff --git a/src/configure.in b/src/configure.in
index ee70682..df28a24 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -230,7 +230,7 @@
 
 dnl Mac OS X 10.9+ no longer include AvailabilityMacros.h in Carbon
 dnl so we need to include it to have access to version macros.
-AC_CHECK_HEADER(AvailabilityMacros.h, HAVE_AVAILABILITYMACROS_H=1)
+AC_CHECK_HEADERS(AvailabilityMacros.h)
 
 AC_SUBST(OS_EXTRA_SRC)
 AC_SUBST(OS_EXTRA_OBJ)