diff --git a/cmd-command-prompt.c b/cmd-command-prompt.c
index a877897e..bca1a7fc 100644
--- a/cmd-command-prompt.c
+++ b/cmd-command-prompt.c
@@ -77,7 +77,7 @@ cmd_command_prompt_exec(struct cmd *self, struct cmdq_item *item)
 	const char			*type, *s, *input;
 	struct cmd_command_prompt_cdata	*cdata;
 	char				*tmp, *prompts, *prompt, *next_prompt;
-	char				*inputs, *next_input;
+	char				*inputs = NULL, *next_input;
 	u_int				 count = args_count(args);
 	int				 wait = !args_has(args, 'b'), space = 1;
 
diff --git a/control.c b/control.c
index 97f8b761..73286e00 100644
--- a/control.c
+++ b/control.c
@@ -385,7 +385,7 @@ control_pause_pane(struct client *c, struct window_pane *wp)
 }
 
 /* Write a line. */
-static void
+static void printflike(2, 0)
 control_vwrite(struct client *c, const char *fmt, va_list ap)
 {
 	struct control_state	*cs = c->control_state;
diff --git a/log.c b/log.c
index 26569974..ec8f1a07 100644
--- a/log.c
+++ b/log.c
@@ -29,9 +29,6 @@
 static FILE	*log_file;
 static int	 log_level;
 
-static void	 log_event_cb(int, const char *);
-static void	 log_vwrite(const char *, va_list);
-
 /* Log callback for libevent. */
 static void
 log_event_cb(__unused int severity, const char *msg)
@@ -100,7 +97,7 @@ log_close(void)
 }
 
 /* Write a log message. */
-static void
+static void printflike(1, 0)
 log_vwrite(const char *msg, va_list ap)
 {
 	char		*fmt, *out;
diff --git a/tmux.h b/tmux.h
index 366b88d7..4723ffab 100644
--- a/tmux.h
+++ b/tmux.h
@@ -2343,7 +2343,7 @@ struct cmdq_item *cmdq_get_callback1(const char *, cmdq_cb, void *);
 struct cmdq_item *cmdq_get_error(const char *);
 struct cmdq_item *cmdq_insert_after(struct cmdq_item *, struct cmdq_item *);
 struct cmdq_item *cmdq_append(struct client *, struct cmdq_item *);
-void		 cmdq_insert_hook(struct session *, struct cmdq_item *,
+void printflike(4, 5) cmdq_insert_hook(struct session *, struct cmdq_item *,
 		     struct cmd_find_state *, const char *, ...);
 void		 cmdq_continue(struct cmdq_item *);
 u_int		 cmdq_next(struct client *);
@@ -2399,7 +2399,7 @@ void	 file_fire_done(struct client_file *);
 void	 file_fire_read(struct client_file *);
 int	 file_can_print(struct client *);
 void printflike(2, 3) file_print(struct client *, const char *, ...);
-void	 file_vprint(struct client *, const char *, va_list);
+void printflike(2, 0) file_vprint(struct client *, const char *, va_list);
 void	 file_print_buffer(struct client *, void *, size_t);
 void printflike(2, 3) file_error(struct client *, const char *, ...);
 void	 file_write(struct client *, const char *, int, const void *, size_t,
@@ -2499,7 +2499,8 @@ struct style_range *status_get_range(struct client *, u_int, u_int);
 void	 status_init(struct client *);
 void	 status_free(struct client *);
 int	 status_redraw(struct client *);
-void status_message_set(struct client *, int, int, int, const char *, ...);
+void printflike(5, 6) status_message_set(struct client *, int, int, int,
+	     const char *, ...);
 void	 status_message_clear(struct client *);
 int	 status_message_redraw(struct client *);
 void	 status_prompt_set(struct client *, struct cmd_find_state *,
@@ -2654,7 +2655,7 @@ void printflike(3, 4) screen_write_puts(struct screen_write_ctx *,
 	     const struct grid_cell *, const char *, ...);
 void printflike(4, 5) screen_write_nputs(struct screen_write_ctx *,
 	     ssize_t, const struct grid_cell *, const char *, ...);
-void	 screen_write_vnputs(struct screen_write_ctx *, ssize_t,
+void printflike(4, 0) screen_write_vnputs(struct screen_write_ctx *, ssize_t,
 	     const struct grid_cell *, const char *, va_list);
 void	 screen_write_putc(struct screen_write_ctx *, const struct grid_cell *,
 	     u_char);
@@ -2923,7 +2924,8 @@ extern const struct window_mode window_client_mode;
 extern const struct window_mode window_copy_mode;
 extern const struct window_mode window_view_mode;
 void printflike(2, 3) window_copy_add(struct window_pane *, const char *, ...);
-void		 window_copy_vadd(struct window_pane *, const char *, va_list);
+void printflike(2, 0) window_copy_vadd(struct window_pane *, const char *,
+		     va_list);
 void		 window_copy_pageup(struct window_pane *, int);
 void		 window_copy_start_drag(struct client *, struct mouse_event *);
 char		*window_copy_get_word(struct window_pane *, u_int, u_int);
diff --git a/tty-term.c b/tty-term.c
index add71d89..8e07da05 100644
--- a/tty-term.c
+++ b/tty-term.c
@@ -670,7 +670,7 @@ tty_term_read_list(const char *name, int fd, char ***caps, u_int *ncaps,
 	const char				*s;
 	char					 tmp[11];
 
-	if (setupterm(name, fd, &error) != OK) {
+	if (setupterm((char *)name, fd, &error) != OK) {
 		switch (error) {
 		case 1:
 			xasprintf(cause, "can't use hardcopy terminal: %s",
diff --git a/xmalloc.h b/xmalloc.h
index d11d4bf1..26009dd8 100644
--- a/xmalloc.h
+++ b/xmalloc.h
@@ -34,12 +34,14 @@ int	 xasprintf(char **, const char *, ...)
 		__attribute__((__format__ (printf, 2, 3)))
 		__attribute__((__nonnull__ (2)));
 int	 xvasprintf(char **, const char *, va_list)
+		__attribute__((__format__ (printf, 2, 0)))
 		__attribute__((__nonnull__ (2)));
 int	 xsnprintf(char *, size_t, const char *, ...)
 		__attribute__((__format__ (printf, 3, 4)))
 		__attribute__((__nonnull__ (3)))
 		__attribute__((__bounded__ (__string__, 1, 2)));
 int	 xvsnprintf(char *, size_t, const char *, va_list)
+		__attribute__((__format__ (printf, 3, 0)))
 		__attribute__((__nonnull__ (3)))
 		__attribute__((__bounded__ (__string__, 1, 2)));