diff --git a/ares_version.h b/ares_version.h
index 66d4bcc7..517e8a9a 100644
--- a/ares_version.h
+++ b/ares_version.h
@@ -12,9 +12,11 @@
 #define ARES_VERSION_STR "1.6.1-CVS"
 
 #if (ARES_VERSION >= 0x010601)
+#  define CARES_HAVE_ARES_FREE_DATA 1
 #  define CARES_HAVE_ARES_LIBRARY_INIT 1
 #  define CARES_HAVE_ARES_LIBRARY_CLEANUP 1
 #else
+#  undef CARES_HAVE_ARES_FREE_DATA
 #  undef CARES_HAVE_ARES_LIBRARY_INIT
 #  undef CARES_HAVE_ARES_LIBRARY_CLEANUP
 #endif