diff --git a/dotfiles/tmux.nix b/dotfiles/tmux.nix
index b1d63c4..bee8ae9 100644
--- a/dotfiles/tmux.nix
+++ b/dotfiles/tmux.nix
@@ -5,6 +5,7 @@
     shortcut = "a";
     keyMode = "vi";
     secureSocket = false;
+    baseIndex = 1;
     extraConfig = ''
       set -ga terminal-overrides ",*col*:Tc"