diff --git a/cmd-show-messages.c b/cmd-show-messages.c
index 92ac5cc2..3d2edf9a 100644
--- a/cmd-show-messages.c
+++ b/cmd-show-messages.c
@@ -61,7 +61,6 @@ cmd_show_messages_server(struct cmd_q *cmdq)
 
 	cmdq_print(cmdq, "started %s", tim);
 	cmdq_print(cmdq, "socket path %s", socket_path);
-	cmdq_print(cmdq, "debug level %d", debug_level);
 	cmdq_print(cmdq, "protocol version %d", PROTOCOL_VERSION);
 
 	return (1);
diff --git a/log.c b/log.c
index 6c7be8b2..46f1673c 100644
--- a/log.c
+++ b/log.c
@@ -22,30 +22,53 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 #include <vis.h>
 
 #include "tmux.h"
 
-FILE	*log_file;
+static FILE	*log_file;
+static int	 log_level;
 
-void	 log_event_cb(int, const char *);
-void	 log_vwrite(const char *, va_list);
+static void	 log_event_cb(int, const char *);
+static void	 log_vwrite(const char *, va_list);
 
 /* Log callback for libevent. */
-void
+static void
 log_event_cb(__unused int severity, const char *msg)
 {
 	log_debug("%s", msg);
 }
 
+/* Increment log level. */
+void
+log_add_level(void)
+{
+	log_level++;
+}
+
+/* Get log level. */
+int
+log_get_level(void)
+{
+	return (log_level);
+}
+
 /* Open logging to file. */
 void
-log_open(const char *path)
+log_open(const char *name)
 {
+	char	*path;
+
+	if (log_level == 0)
+		return;
+
 	if (log_file != NULL)
 		fclose(log_file);
 
+	xasprintf(&path, "tmux-%s-%ld.log", name, (long)getpid());
 	log_file = fopen(path, "w");
+	free(path);
 	if (log_file == NULL)
 		return;
 
@@ -65,7 +88,7 @@ log_close(void)
 }
 
 /* Write a log message. */
-void
+static void
 log_vwrite(const char *msg, va_list ap)
 {
 	char		*fmt, *out;
diff --git a/proc.c b/proc.c
index 31fd136b..06340cd9 100644
--- a/proc.c
+++ b/proc.c
@@ -188,7 +188,7 @@ proc_start(const char *name, struct event_base *base, int forkflag,
 			fatalx("event_reinit failed");
 	}
 
-	logfile(name);
+	log_open(name);
 	setproctitle("%s (%s)", name, socket_path);
 
 	log_debug("%s started (%ld): socket %s, protocol %d", name,
diff --git a/server.c b/server.c
index e17b9356..e9159422 100644
--- a/server.c
+++ b/server.c
@@ -173,7 +173,7 @@ server_start(struct event_base *base, int lockfd, char *lockfile)
 	}
 	close(pair[0]);
 
-	if (debug_level > 3)
+	if (log_get_level() > 3)
 		tty_create_log();
 	if (pledge("stdio rpath wpath cpath fattr unix getpw recvfd proc exec "
 	    "tty ps", NULL) != 0)
diff --git a/tmux.c b/tmux.c
index aa827178..f5383fcf 100644
--- a/tmux.c
+++ b/tmux.c
@@ -44,7 +44,6 @@ struct options	*global_w_options;	/* window options */
 struct environ	*global_environ;
 
 char		*shell_cmd;
-int		 debug_level;
 time_t		 start_time;
 char		 socket_path[PATH_MAX];
 
@@ -61,18 +60,6 @@ usage(void)
 	exit(1);
 }
 
-void
-logfile(const char *name)
-{
-	char	*path;
-
-	if (debug_level > 0) {
-		xasprintf(&path, "tmux-%s-%ld.log", name, (long) getpid());
-		log_open(path);
-		free(path);
-	}
-}
-
 const char *
 getshell(void)
 {
@@ -243,7 +230,7 @@ main(int argc, char **argv)
 			flags |= CLIENT_UTF8;
 			break;
 		case 'v':
-			debug_level++;
+			log_add_level();
 			break;
 		default:
 			usage();
diff --git a/tmux.h b/tmux.h
index 591fe54e..5f469f92 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1432,10 +1432,8 @@ extern struct options *global_s_options;
 extern struct options *global_w_options;
 extern struct environ *global_environ;
 extern char	*shell_cmd;
-extern int	 debug_level;
 extern time_t	 start_time;
 extern char	 socket_path[PATH_MAX];
-void		 logfile(const char *);
 const char	*getshell(void);
 int		 checkshell(const char *);
 int		 areshell(const char *);
@@ -2210,8 +2208,10 @@ char		*utf8_padcstr(const char *, u_int);
 char   *get_proc_name(int, char *);
 
 /* log.c */
-void		 log_open(const char *);
-void		 log_close(void);
+void	log_add_level(void);
+int	log_get_level(void);
+void	log_open(const char *);
+void	log_close(void);
 void printflike(1, 2) log_debug(const char *, ...);
 __dead void printflike(1, 2) fatal(const char *, ...);
 __dead void printflike(1, 2) fatalx(const char *, ...);