diff --git a/nixos/modules/programs/fish.nix b/nixos/modules/programs/fish.nix
index 48b324a0fe83..39b92edf2ac2 100644
--- a/nixos/modules/programs/fish.nix
+++ b/nixos/modules/programs/fish.nix
@@ -102,6 +102,9 @@ in
 
     programs.fish.shellAliases = mapAttrs (name: mkDefault) cfge.shellAliases;
 
+    # Required for man completions
+    documentation.man.generateCaches = true;
+
     environment.etc."fish/foreign-env/shellInit".text = cfge.shellInit;
     environment.etc."fish/foreign-env/loginShellInit".text = cfge.loginShellInit;
     environment.etc."fish/foreign-env/interactiveShellInit".text = cfge.interactiveShellInit;