diff --git a/tmuxssh.py b/tmuxssh.py
index 354689e..1427dd2 100755
--- a/tmuxssh.py
+++ b/tmuxssh.py
@@ -29,7 +29,7 @@ def tmux(self, *args):
         return subprocess.call(['tmux'] + list(args))
 
     def split_window(self, command):
-        self.tmux('split-window', '-t', self._session_name, command)
+        self.tmux('split-window', '-dt', self._session_name, command)
 
     def select_layout(self, layout):
         self.tmux('select-layout', '-t', self._session_name, layout)
@@ -41,7 +41,7 @@ def set_window_option(self, option, value):
         self.tmux('set-window-option', '-t', self._session_name, option, value)
 
     def kill_pane(self, n):
-        self.tmux('kill-pane', '-t', str(n))
+        self.tmux('kill-pane', '-t', '{}:{}'.format(self._session_name, n))
 
     def kill_session(self):
         self.tmux('kill-session', '-t', self._session_name)
@@ -68,6 +68,9 @@ def main():
         hosts = (h for host in args.get('<host>') for h in host.split())
         template = args.get('--template') or 'ssh {}'
         commands = (ssh_command(host, template) for host in hosts)
+        # Allow nesting inside another tmux session.
+        # (Should be safe,since we're creating a new session anyway).
+        os.environ.pop('TMUX')
         tmux_commands(commands)
     except EnvironmentError:
         print('You need to install tmux before using this script.')