diff --git a/terminal-software.nix b/terminal-software.nix
index d46fe92..83cc27e 100644
--- a/terminal-software.nix
+++ b/terminal-software.nix
@@ -37,7 +37,7 @@
 
   programs.tmux = {
     enable = true;
-    historyLimit = 600000;
+    historyLimit = 60000;
     escapeTime = 10;
     keyMode = "vi";
     mouse = true;
@@ -47,6 +47,8 @@
       bind-key 'Space' copy-mode
       set -g status-right "#{net_speed} #{cpu_percentage}"
       set -g default-terminal "tmux-256color"
+      set -as terminal-overrides ',*:Smulx=\E[4::%p1%dm'  # undercurl support
+      set -as terminal-overrides ',*:Setulc=\E[58::2::%p1%{65536}%/%d::%p1%{256}%/%{255}%&%d::%p1%{255}%&%d%;m'  # underscore colours - needs tmux-3.0
       run-shell ${pkgs.tmuxPlugins.net-speed}/share/tmux-plugins/net-speed/net_speed.tmux
       run-shell ${pkgs.tmuxPlugins.cpu}/share/tmux-plugins/cpu/cpu.tmux
     '';