diff --git a/nixos/modules/programs/fish.nix b/nixos/modules/programs/fish.nix
index 39b715369bb6..13c00237906e 100644
--- a/nixos/modules/programs/fish.nix
+++ b/nixos/modules/programs/fish.nix
@@ -170,6 +170,7 @@ in
 
     # Required for man completions
     documentation.man.cache.enable = lib.mkDefault true;
+    documentation.man.cache.generateAtRuntime = lib.mkDefault true;
 
     environment = lib.mkMerge [
       (lib.mkIf cfg.useBabelfish {