diff --git a/cmd-if-shell.c b/cmd-if-shell.c
index bdd7699d..a290f09f 100644
--- a/cmd-if-shell.c
+++ b/cmd-if-shell.c
@@ -28,6 +28,7 @@
  * Executes a tmux command if a shell command returns true.
  */
 
+int	cmd_if_shell_check(struct args *);
 int	cmd_if_shell_exec(struct cmd *, struct cmd_ctx *);
 
 void	cmd_if_shell_callback(struct job *);
@@ -35,19 +36,30 @@ void	cmd_if_shell_free(void *);
 
 const struct cmd_entry cmd_if_shell_entry = {
 	"if-shell", "if",
-	"", 2, 2,
-	"shell-command command",
+	"", 2, 4,
+	"shell-command command [else command]",
 	0,
 	NULL,
-	NULL,
+	cmd_if_shell_check,
 	cmd_if_shell_exec
 };
 
 struct cmd_if_shell_data {
-	char		*cmd;
+	char		*cmd_if;
+	char		*cmd_else;
 	struct cmd_ctx	 ctx;
 };
 
+int
+cmd_if_shell_check(struct args *args)
+{
+	if (args->argc == 3)
+		return (-1);
+	if (args->argc == 4 && strcmp(args->argv[2], "else") != 0)
+		return (-1);
+	return (0);
+}
+
 int
 cmd_if_shell_exec(struct cmd *self, struct cmd_ctx *ctx)
 {
@@ -56,7 +68,11 @@ cmd_if_shell_exec(struct cmd *self, struct cmd_ctx *ctx)
 	const char			*shellcmd = args->argv[0];
 
 	cdata = xmalloc(sizeof *cdata);
-	cdata->cmd = xstrdup(args->argv[1]);
+	cdata->cmd_if = xstrdup(args->argv[1]);
+	if (args->argc == 4)
+		cdata->cmd_else = xstrdup(args->argv[3]);
+	else
+		cdata->cmd_else = NULL;
 	memcpy(&cdata->ctx, ctx, sizeof cdata->ctx);
 
 	if (ctx->cmdclient != NULL)
@@ -75,12 +91,16 @@ cmd_if_shell_callback(struct job *job)
 	struct cmd_if_shell_data	*cdata = job->data;
 	struct cmd_ctx			*ctx = &cdata->ctx;
 	struct cmd_list			*cmdlist;
+	char				*cmd;
 	char				*cause;
 
-	if (!WIFEXITED(job->status) || WEXITSTATUS(job->status) != 0)
-		return;
-
-	if (cmd_string_parse(cdata->cmd, &cmdlist, &cause) != 0) {
+	if (!WIFEXITED(job->status) || WEXITSTATUS(job->status) != 0) {
+		cmd = cdata->cmd_else;
+		if (cmd == NULL)
+			return;
+	} else
+		cmd = cdata->cmd_if;
+	if (cmd_string_parse(cmd, &cmdlist, &cause) != 0) {
 		if (cause != NULL) {
 			ctx->error(ctx, "%s", cause);
 			xfree(cause);
@@ -107,6 +127,8 @@ cmd_if_shell_free(void *data)
 	if (ctx->curclient != NULL)
 		ctx->curclient->references--;
 
-	xfree(cdata->cmd);
+	if (cdata->cmd_else != NULL)
+		xfree(cdata->cmd_else);
+	xfree(cdata->cmd_if);
 	xfree(cdata);
 }