diff --git a/lib/asyn-thread.c b/lib/asyn-thread.c
index 5982983082..970ec1ffb3 100644
--- a/lib/asyn-thread.c
+++ b/lib/asyn-thread.c
@@ -69,7 +69,7 @@
 #ifdef USE_ARES
 #include <ares.h>
 #ifdef USE_HTTPSRR
-#define USE_HTTPSRR_ARES 1 /* the combo */
+#define USE_HTTPSRR_ARES  /* the combo */
 #endif
 #endif