diff --git a/shared/cli/shell.nix b/shared/cli/shell.nix
index 6e0274f..8ddf0f8 100644
--- a/shared/cli/shell.nix
+++ b/shared/cli/shell.nix
@@ -20,7 +20,10 @@
     programs.fish = {
       enable = true;
       interactiveShellInit = ''
-        if test $COLUMNS -ge 120; and test $LINES -ge 30
+        set -l dimensions (stty size 2>/dev/null | string split ' ')
+        set -l rows $dimensions[1]
+        set -l cols $dimensions[2]
+        if test -n "$cols" -a "$cols" -ge 120 -a "$rows" -ge 30
           fastfetch -l nixos2 --logo-padding-right 6 --separator " " --structure "break:break:title:break:os:kernel:packages:disk:shell:terminal:wm:uptime:media:break:colors"
         end