diff --git a/cmd-server-info.c b/cmd-server-info.c
index daa08572..14212478 100644
--- a/cmd-server-info.c
+++ b/cmd-server-info.c
@@ -68,8 +68,9 @@ cmd_server_info_exec(unused struct cmd *self, struct cmd_ctx *ctx)
 	tim = ctime(&start_time);
 	*strchr(tim, '\n') = '\0';
 	ctx->print(ctx, "pid %ld, started %s", (long) getpid(), tim);
-	ctx->print(ctx, "socket path %s, debug level %d%s",
-	    socket_path, debug_level, be_quiet ? ", quiet" : "");
+	ctx->print(ctx, "socket path %s, debug level %d%s%s",
+	    socket_path, debug_level, be_quiet ? ", quiet" : "",
+	    login_shell ? ", login shell" : "");
         if (uname(&un) == 0) {
                 ctx->print(ctx, "system is %s %s %s %s",
 		    un.sysname, un.release, un.version, un.machine);
diff --git a/tmux.1 b/tmux.1
index 61d77b75..f3a36fe8 100644
--- a/tmux.1
+++ b/tmux.1
@@ -23,7 +23,7 @@
 .Sh SYNOPSIS
 .Nm tmux
 .Bk -words
-.Op Fl 28dqUuv
+.Op Fl 28dlqUuv
 .Op Fl f Ar file
 .Op Fl L Ar socket-name
 .Op Fl S Ar socket-path
@@ -120,6 +120,10 @@ commands which are executed in sequence when the server is first started.
 If a command in the configuration file fails,
 .Nm
 will report an error and exit without executing further commands.
+.It Fl l
+Behave as a login shell.
+This flag currently has no effect and is for compatibility with other shells
+when using tmux as a login shell.
 .It Fl L Ar socket-name
 .Nm
 stores the server socket in a directory under
diff --git a/tmux.c b/tmux.c
index 01f7d6c3..fce1e4d9 100644
--- a/tmux.c
+++ b/tmux.c
@@ -57,6 +57,7 @@ int		 debug_level;
 int		 be_quiet;
 time_t		 start_time;
 char		*socket_path;
+int		 login_shell;
 
 __dead void	 usage(void);
 char 		*makesockpath(const char *);
@@ -68,8 +69,8 @@ __dead void
 usage(void)
 {
 	fprintf(stderr,
-	    "usage: %s [-28dqUuv] [-f file] [-L socket-name] [-S socket-path]\n"
-	    "            [command [flags]]\n",
+	    "usage: %s [-28dlqUuv] [-f file] [-L socket-name]\n"
+	    "            [-S socket-path] [command [flags]]\n",
 	    __progname);
 	exit(1);
 }
@@ -316,8 +317,9 @@ main(int argc, char **argv)
 
 	unlock = flags = 0;
 	label = path = NULL;
-        while ((opt = getopt(argc, argv, "28df:L:qS:uUv")) != -1) {
-                switch (opt) {
+	login_shell = (**argv == '-');
+	while ((opt = getopt(argc, argv, "28df:lL:qS:uUv")) != -1) {
+		switch (opt) {
 		case '2':
 			flags |= IDENTIFY_256COLOURS;
 			flags &= ~IDENTIFY_88COLOURS;
@@ -334,6 +336,9 @@ main(int argc, char **argv)
 				xfree(cfg_file);
 			cfg_file = xstrdup(optarg);
 			break;
+		case 'l':
+			login_shell = 1;
+			break;
 		case 'L':
 			if (label != NULL)
 				xfree(label);
diff --git a/tmux.h b/tmux.h
index 57d5bf4b..778346fa 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1117,6 +1117,7 @@ extern int	 debug_level;
 extern int	 be_quiet;
 extern time_t	 start_time;
 extern char 	*socket_path;
+extern int	 login_shell;
 void		 logfile(const char *);
 void		 siginit(void);
 void		 sigreset(void);