diff --git a/ares/ares_free_errmem.c b/ares/ares_free_errmem.c
index b255d2365..128407fb0 100644
--- a/ares/ares_free_errmem.c
+++ b/ares/ares_free_errmem.c
@@ -21,4 +21,5 @@
  */
 void ares_free_errmem(char *mem)
 {
+  (void)mem;
 }