diff --git a/appl/ftp/ftpd/auth.h b/appl/ftp/ftpd/auth.h
index 79b2df60b..317a7e06f 100644
--- a/appl/ftp/ftpd/auth.h
+++ b/appl/ftp/ftpd/auth.h
@@ -93,8 +93,16 @@ void enc(char*);
 int auth_read(int, void*, int);
 int auth_write(int, void*, int);
 
-void auth_vprintf(const char *fmt, va_list ap);
-void auth_printf(const char *fmt, ...);
+void auth_vprintf(const char *fmt, va_list ap)
+#ifdef __GNUC__
+__attribute__ ((format (printf, 1, 0)))
+#endif
+;
+void auth_printf(const char *fmt, ...)
+#ifdef __GNUC__
+__attribute__ ((format (printf, 1, 2)))
+#endif
+;
 
 void new_ftp_command(char *command);
 
diff --git a/appl/ftp/ftpd/extern.h b/appl/ftp/ftpd/extern.h
index 6b265d017..f9b800fee 100644
--- a/appl/ftp/ftpd/extern.h
+++ b/appl/ftp/ftpd/extern.h
@@ -65,10 +65,18 @@ int	ftpd_pclose(FILE *);
 FILE   *ftpd_popen(char *, char *, int, int);
 char   *getline(char *, int);
 void	logwtmp(char *, char *, char *);
-void	lreply(int, const char *, ...);
+void	lreply(int, const char *, ...)
+#ifdef __GNUC__
+__attribute__ ((format (printf, 2, 3)))
+#endif
+;
 void	makedir(char *);
 void	nack(char *);
-void	nreply(const char *, ...);
+void	nreply(const char *, ...)
+#ifdef __GNUC__
+__attribute__ ((format (printf, 1, 2)))
+#endif
+;
 void	pass(char *);
 void	passive(void);
 void	perror_reply(int, char *);
@@ -76,10 +84,18 @@ void	pwd(void);
 void	removedir(char *);
 void	renamecmd(char *, char *);
 char   *renamefrom(char *);
-void	reply(int, const char *, ...);
+void	reply(int, const char *, ...)
+#ifdef __GNUC__
+__attribute__ ((format (printf, 2, 3)))
+#endif
+;
 void	retrieve(char *, char *);
 void	send_file_list(char *);
-void	setproctitle(const char *, ...);
+void	setproctitle(const char *, ...)
+#ifdef __GNUC__
+__attribute__ ((format (printf, 1, 2)))
+#endif
+;
 void	statcmd(void);
 void	statfilecmd(char *);
 void	do_store(char *, char *, int);
diff --git a/appl/ftp/ftpd/ftpcmd.y b/appl/ftp/ftpd/ftpcmd.y
index 769fe73da..9dab80fde 100644
--- a/appl/ftp/ftpd/ftpcmd.y
+++ b/appl/ftp/ftpd/ftpcmd.y
@@ -1373,7 +1373,7 @@ sizecmd(char *filename)
 		if (stat(filename, &stbuf) < 0 || !S_ISREG(stbuf.st_mode))
 			reply(550, "%s: not a plain file.", filename);
 		else
-			reply(213, "%qu", stbuf.st_size);
+			reply(213, "%lu", (unsigned long)stbuf.st_size);
 		break; }
 	case TYPE_A: {
 		FILE *fin;
diff --git a/appl/ftp/ftpd/ftpd.c b/appl/ftp/ftpd/ftpd.c
index 49dd735e5..9f57d0941 100644
--- a/appl/ftp/ftpd/ftpd.c
+++ b/appl/ftp/ftpd/ftpd.c
@@ -1542,6 +1542,13 @@ fatal(char *s)
 	/* NOTREACHED */
 }
 
+static void
+int_reply(int, char *, const char *, va_list)
+#ifdef __GNUC__
+__attribute__ ((format (printf, 3, 0)))
+#endif
+;
+
 static void
 int_reply(int n, char *c, const char *fmt, va_list ap)
 {
diff --git a/appl/kx/kxd.c b/appl/kx/kxd.c
index bd5ac94f3..81b581fa1 100644
--- a/appl/kx/kxd.c
+++ b/appl/kx/kxd.c
@@ -57,6 +57,15 @@ childhandler (int sig)
      SIGRETURN(0);
 }
 
+static void
+fatal(int, des_cblock *, des_key_schedule,
+      struct sockaddr_in *, struct sockaddr_in *,
+      char *format, ...)
+#ifdef __GNUC__
+__attribute__ ((format (printf, 6, 7)))
+#endif
+;
+
 static void
 fatal (int fd, des_cblock *key, des_key_schedule schedule,
        struct sockaddr_in *thisaddr,
diff --git a/appl/popper/pop_dele.c b/appl/popper/pop_dele.c
index dfd9528d9..0c4b68da0 100644
--- a/appl/popper/pop_dele.c
+++ b/appl/popper/pop_dele.c
@@ -36,8 +36,9 @@ pop_dele (POP *p)
 
 #ifdef DEBUG
     if(p->debug)
-        pop_log(p,POP_DEBUG,"Deleting message %u at offset %u of length %u\n",
-            mp->number,mp->offset,mp->length);
+        pop_log(p, POP_DEBUG,
+		"Deleting message %u at offset %ld of length %ld\n",
+		mp->number, mp->offset, mp->length);
 #endif /* DEBUG */
 
     /*  Update the messages_deleted and bytes_deleted counters */
diff --git a/appl/popper/pop_dropcopy.c b/appl/popper/pop_dropcopy.c
index 9a78b5146..9f067d851 100644
--- a/appl/popper/pop_dropcopy.c
+++ b/appl/popper/pop_dropcopy.c
@@ -71,7 +71,10 @@ pop_dropcopy(POP *p, struct passwd *pwp)
     	setgid(pwp->pw_gid);
     }
 #ifdef DEBUG
-    if(p->debug)pop_log(p,POP_DEBUG,"uid = %d, gid = %d",getuid(),getgid());
+    if(p->debug)
+       pop_log(p, POP_DEBUG,"uid = %u, gid = %u",
+	       (unsigned)getuid(),
+	       (unsigned)getgid());
 #endif /* DEBUG */
 
     /* Open for append,  this solves the crash recovery problem */
diff --git a/appl/popper/pop_dropinfo.c b/appl/popper/pop_dropinfo.c
index 389ae4b37..c8f1e805c 100644
--- a/appl/popper/pop_dropinfo.c
+++ b/appl/popper/pop_dropinfo.c
@@ -133,7 +133,7 @@ pop_dropinfo(POP *p)
 #ifdef DEBUG
             if(p->debug)
                 pop_log(p, POP_DEBUG,
-			"Msg %d at offset %u being added to list",
+			"Msg %d at offset %ld being added to list",
 			mp->number, mp->offset);
 #endif /* DEBUG */
         }else if(in_header){
@@ -191,8 +191,8 @@ pop_dropinfo(POP *p)
         int i;
         for (i = 0, mp = p->mlp; i < p->msg_count; i++, mp++)
 #ifdef UIDL
-            pop_log(p,POP_DEBUG,
-                "Msg %d at offset %d is %d octets long and has %u lines and id %s.",
+	    pop_log(p,POP_DEBUG,
+		    "Msg %d at offset %ld is %ld octets long and has %u lines and id %s.",
                     mp->number,mp->offset,mp->length,mp->lines, mp->msg_id);
 #else	
             pop_log(p,POP_DEBUG,
diff --git a/appl/popper/pop_list.c b/appl/popper/pop_list.c
index 3d0894720..ae11ae9b4 100644
--- a/appl/popper/pop_list.c
+++ b/appl/popper/pop_list.c
@@ -36,13 +36,14 @@ pop_list (POP *p)
                 "Message %d has been deleted.",msg_num));
 
         /*  Display message information */
-        return (pop_msg(p,POP_SUCCESS,"%u %u",msg_num,mp->length));
+        return (pop_msg(p,POP_SUCCESS,"%d %ld",msg_num,mp->length));
     }
     
     /*  Display the entire list of messages */
     pop_msg(p,POP_SUCCESS,
-        "%u messages (%u octets)",
-            p->msg_count-p->msgs_deleted,p->drop_size-p->bytes_deleted);
+	    "%d messages (%ld octets)",
+            p->msg_count-p->msgs_deleted,
+	    p->drop_size-p->bytes_deleted);
 
     /*  Loop through the message information list.  Skip deleted messages */
     for (i = p->msg_count, mp = p->mlp; i > 0; i--, mp++) {
diff --git a/appl/popper/pop_pass.c b/appl/popper/pop_pass.c
index 3353af6f8..71e8c44e3 100644
--- a/appl/popper/pop_pass.c
+++ b/appl/popper/pop_pass.c
@@ -93,6 +93,6 @@ pop_pass (POP *p)
 
     /*  Authorization completed successfully */
     return (pop_msg (p, POP_SUCCESS,
-		     "%s has %d message(s) (%d octets).",
+		     "%s has %d message(s) (%ld octets).",
 		     p->user, p->msg_count, p->drop_size));
 }
diff --git a/appl/popper/pop_rset.c b/appl/popper/pop_rset.c
index 3e0716701..e8b89ed30 100644
--- a/appl/popper/pop_rset.c
+++ b/appl/popper/pop_rset.c
@@ -28,6 +28,6 @@ pop_rset (POP *p)
     /*  Reset the last-message-access flag */
     p->last_msg = 0;
 
-    return (pop_msg(p,POP_SUCCESS,"Maildrop has %u messages (%u octets)",
-        p->msg_count,p->drop_size));
+    return (pop_msg(p,POP_SUCCESS,"Maildrop has %u messages (%ld octets)",
+		    p->msg_count, p->drop_size));
 }
diff --git a/appl/popper/pop_send.c b/appl/popper/pop_send.c
index f37afed5a..05ae38aa0 100644
--- a/appl/popper/pop_send.c
+++ b/appl/popper/pop_send.c
@@ -84,7 +84,7 @@ pop_send(POP *p)
     }
     
     /*  Display the number of bytes in the message */
-    pop_msg(p,POP_SUCCESS,"%u octets",mp->length);
+    pop_msg(p, POP_SUCCESS, "%ld octets", mp->length);
 
     /*  Position to the start of the message */
     fseek(p->drop,mp->offset,0);
diff --git a/appl/popper/pop_stat.c b/appl/popper/pop_stat.c
index a58267604..a4c6f3346 100644
--- a/appl/popper/pop_stat.c
+++ b/appl/popper/pop_stat.c
@@ -15,10 +15,12 @@ int
 pop_stat (POP *p)
 {
 #ifdef DEBUG
-    if (p->debug) pop_log(p,POP_DEBUG,"%d message(s) (%d octets).",
+    if (p->debug) pop_log(p,POP_DEBUG,"%d message(s) (%ld octets).",
 			  p->msg_count-p->msgs_deleted,
 			  p->drop_size-p->bytes_deleted);
 #endif /* DEBUG */
     return (pop_msg (p,POP_SUCCESS,
-        "%u %u",p->msg_count-p->msgs_deleted,p->drop_size-p->bytes_deleted));
+		     "%d %ld",
+		     p->msg_count-p->msgs_deleted,
+		     p->drop_size-p->bytes_deleted));
 }
diff --git a/appl/popper/pop_uidl.c b/appl/popper/pop_uidl.c
index 5a0c8f74c..1cc2803f6 100644
--- a/appl/popper/pop_uidl.c
+++ b/appl/popper/pop_uidl.c
@@ -74,8 +74,9 @@ pop_uidl (POP *p)
     
     /*  Display the entire list of messages */
     pop_msg(p,POP_SUCCESS,
-        "%u messages (%u octets)",
-            p->msg_count-p->msgs_deleted,p->drop_size-p->bytes_deleted);
+	    "%d messages (%ld octets)",
+            p->msg_count-p->msgs_deleted,
+	    p->drop_size-p->bytes_deleted);
 
     /*  Loop through the message information list.  Skip deleted messages */
     for (i = p->msg_count, mp = p->mlp; i > 0; i--, mp++) {
diff --git a/appl/popper/pop_xover.c b/appl/popper/pop_xover.c
index a77b01a57..8b8f5988f 100644
--- a/appl/popper/pop_xover.c
+++ b/appl/popper/pop_xover.c
@@ -9,8 +9,9 @@ pop_xover (POP *p)
     int		            i;
 
     pop_msg(p,POP_SUCCESS,
-	    "%u messages (%u octets)",
-            p->msg_count-p->msgs_deleted,p->drop_size-p->bytes_deleted);
+	    "%d messages (%ld octets)",
+            p->msg_count-p->msgs_deleted,
+	    p->drop_size-p->bytes_deleted);
     
     /*  Loop through the message information list.  Skip deleted messages */
     for (i = p->msg_count, mp = p->mlp; i > 0; i--, mp++) {
diff --git a/appl/popper/popper.c b/appl/popper/popper.c
index 4d3401bc2..8671cf116 100644
--- a/appl/popper/popper.c
+++ b/appl/popper/popper.c
@@ -75,14 +75,16 @@ main (int argc, char **argv)
 
     for (p.CurrentState=auth1;p.CurrentState!=halt&&p.CurrentState!=error;) {
         if (hangup) {
-            pop_msg(&p,POP_FAILURE,"POP hangup",p.myhost);
+            pop_msg(&p, POP_FAILURE, "POP hangup: %s", p.myhost);
             if (p.CurrentState > auth2 && !pop_updt(&p))
-                pop_msg(&p,POP_FAILURE,"POP mailbox update failed.",p.myhost);
+                pop_msg(&p, POP_FAILURE,
+			"POP mailbox update failed: %s", p.myhost);
             p.CurrentState = error;
-        } else if (tgets(message,MAXLINELEN,p.input,pop_timeout) == NULL) {
-	    pop_msg(&p,POP_FAILURE,"POP timeout",p.myhost);
+        } else if (tgets(message, MAXLINELEN, p.input, pop_timeout) == NULL) {
+	    pop_msg(&p, POP_FAILURE, "POP timeout: %s", p.myhost);
 	    if (p.CurrentState > auth2 && !pop_updt(&p))
-                pop_msg(&p,POP_FAILURE,"POP mailbox update failed!",p.myhost);
+                pop_msg(&p,POP_FAILURE,
+			"POP mailbox update failed: %s", p.myhost);
             p.CurrentState = error;
         }
         else {