diff --git a/ares/setup_once.h b/ares/setup_once.h
index e1c5af278666be7baeb084111324a603815f15c2..4a71c29194742aecd75f27110e5d853c4820557d 100644
--- a/ares/setup_once.h
+++ b/ares/setup_once.h
@@ -223,7 +223,7 @@ struct timeval {
 
 
 #ifdef RECVFROM_TYPE_ARG6_IS_VOID
-#  define RECVFROM_ARG6_T unsigned int
+#  define RECVFROM_ARG6_T int
 #else
 #  define RECVFROM_ARG6_T RECVFROM_TYPE_ARG6
 #endif
diff --git a/lib/setup_once.h b/lib/setup_once.h
index e96f6984aead516bac87130688d2704a12758a13..82d74e72f7d33116b623e84b692b026b5800f927 100644
--- a/lib/setup_once.h
+++ b/lib/setup_once.h
@@ -230,7 +230,7 @@ struct timeval {
 
 
 #ifdef RECVFROM_TYPE_ARG6_IS_VOID
-#  define RECVFROM_ARG6_T unsigned int
+#  define RECVFROM_ARG6_T int
 #else
 #  define RECVFROM_ARG6_T RECVFROM_TYPE_ARG6
 #endif