diff --git a/lib/libntp/getopt.c b/lib/libntp/getopt.c
index 8505d808d430..7e7d85f72d39 100644
--- a/lib/libntp/getopt.c
+++ b/lib/libntp/getopt.c
@@ -30,6 +30,8 @@ int	ntp_optopt;	/* for compatibility, option character checked */
 static char	*scan = NULL;	/* Private scan pointer. */
 static char	*prog = "amnesia";
 
+static int badopt __P((char *, int));
+
 /*
  * Print message about a bad option.
  */
diff --git a/lib/libntp/humandate.c b/lib/libntp/humandate.c
index 9108998f39f9..05b29f6ed05f 100644
--- a/lib/libntp/humandate.c
+++ b/lib/libntp/humandate.c
@@ -12,6 +12,8 @@
 #include <time.h>
 #endif
 
+char *humanlogtime __P((void));
+
 static char *months[] = {
         "Jan", "Feb", "Mar", "Apr", "May", "Jun",
         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
diff --git a/lib/libntp/lib_strbuf.c b/lib/libntp/lib_strbuf.c
index 7a88c98c251d..efc5c6f3133d 100644
--- a/lib/libntp/lib_strbuf.c
+++ b/lib/libntp/lib_strbuf.c
@@ -2,6 +2,8 @@
  * lib_strbuf - library string storage
  */
 
+#include <sys/cdefs.h>
+
 #include "lib_strbuf.h"
 
 /*
@@ -11,6 +13,8 @@ char lib_stringbuf[LIB_NUMBUFS][LIB_BUFLENGTH];
 int lib_nextbuf;
 int lib_inited = 0;
 
+void init_lib __P((void));
+
 /*
  * initialization routine.  Might be needed if the code is ROMized.
  */