diff --git a/nixos/modules/services/monitoring/munin.nix b/nixos/modules/services/monitoring/munin.nix
index dcdad6fac1b..431d0397546 100644
--- a/nixos/modules/services/monitoring/munin.nix
+++ b/nixos/modules/services/monitoring/munin.nix
@@ -223,6 +223,10 @@ in
 
   }) (mkIf cronCfg.enable {
 
+    # Munin is hardcoded to use DejaVu Mono and the graphs come out wrong if
+    # it's not available.
+    fonts.fonts = [ pkgs.dejavu_fonts ];
+
     systemd.timers.munin-cron = {
       description = "batch Munin master programs";
       wantedBy = [ "timers.target" ];