diff --git a/nixos/modules/config/fonts/fontconfig.nix b/nixos/modules/config/fonts/fontconfig.nix
index 3bfa1893a8ba..6ac64b0ec9c6 100644
--- a/nixos/modules/config/fonts/fontconfig.nix
+++ b/nixos/modules/config/fonts/fontconfig.nix
@@ -45,6 +45,9 @@ let
 
   # generate the font cache setting file for a fontconfig version
   # use latest when no version is passed
+  # When cross-compiling, we can’t generate the cache, so we skip the
+  # <cachedir> part. fontconfig still works but is a little slower in
+  # looking things up.
   makeCacheConf = { version ? null }:
     let
       fcPackage = if version == null
@@ -60,11 +63,13 @@ let
       <fontconfig>
         <!-- Font directories -->
         ${concatStringsSep "\n" (map (font: "<dir>${font}</dir>") config.fonts.fonts)}
+        ${optionalString (pkgs.stdenv.hostPlatform == pkgs.stdenv.buildPlatform) ''
         <!-- Pre-generated font caches -->
         <cachedir>${cache}</cachedir>
         ${optionalString (pkgs.stdenv.isx86_64 && cfg.cache32Bit) ''
           <cachedir>${cache32}</cachedir>
         ''}
+        ''}
       </fontconfig>
     '';