diff --git a/modules/programs/kitty.nix b/modules/programs/kitty.nix
index d9a3081d..698e8034 100644
--- a/modules/programs/kitty.nix
+++ b/modules/programs/kitty.nix
@@ -186,9 +186,13 @@ in {
 
         (optionalString (cfg.theme != null) ''
           include ${pkgs.kitty-themes}/share/kitty-themes/${
-            (head (filter (x: x.name == cfg.theme) (builtins.fromJSON
-              (builtins.readFile
-                "${pkgs.kitty-themes}/share/kitty-themes/themes.json")))).file
+            let
+              matching = filter (x: x.name == cfg.theme) (builtins.fromJSON
+                (builtins.readFile
+                  "${pkgs.kitty-themes}/share/kitty-themes/themes.json"));
+            in throwIf (length matching == 0)
+            "kitty-themes does not contain a theme named ${cfg.theme}"
+            (head matching).file
           }
         '')
         ''