diff --git a/src/explicit_bzero.c b/src/explicit_bzero.c
index 52a7517..d223631 100644
--- a/src/explicit_bzero.c
+++ b/src/explicit_bzero.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: explicit_bzero.c,v 1.3 2014/06/21 02:34:26 matthew Exp $ */
+/*	$OpenBSD: explicit_bzero.c,v 1.4 2015/08/31 02:53:57 guenther Exp $ */
 /*
  * Public domain.
  * Written by Matthew Dempsky.
@@ -6,6 +6,9 @@
 
 #include <string.h>
 
+__attribute__((__weak__)) void
+__explicit_bzero_hook(void *, size_t);
+
 __attribute__((__weak__)) void
 __explicit_bzero_hook(void *buf, size_t len)
 {
diff --git a/src/setproctitle.c b/src/setproctitle.c
index ff32aa3..d3e1087 100644
--- a/src/setproctitle.c
+++ b/src/setproctitle.c
@@ -222,6 +222,10 @@ setproctitle_init(int argc, char *argv[], char *envp[])
 #define SPT_MAXTITLE 255
 #endif
 
+__printflike(1, 2)
+void
+setproctitle_impl(const char *fmt, ...);
+
 void
 setproctitle_impl(const char *fmt, ...)
 {