diff --git a/lib/libc/resolv/h_errno.c b/lib/libc/resolv/h_errno.c
index 88d15aee7f9..8ced7081ddf 100644
--- a/lib/libc/resolv/h_errno.c
+++ b/lib/libc/resolv/h_errno.c
@@ -33,6 +33,9 @@
 #undef	h_errno
 extern int h_errno;
 
+int *__h_errno(void);
+void __h_errno_set(res_state res, int err);
+
 int *
 __h_errno(void)
 {