diff --git a/doc/manual/generate-manpage.nix b/doc/manual/generate-manpage.nix
index e18810594..b41730bc2 100644
--- a/doc/manual/generate-manpage.nix
+++ b/doc/manual/generate-manpage.nix
@@ -75,10 +75,14 @@ let
         (details ? doc)
         (replaceStrings ["@stores@"] [storeDocs] details.doc);
 
-      maybeOptions = optionalString (details.flags != {}) ''
+      maybeOptions = let
+        allVisibleOptions = filterAttrs
+          (_: o: ! o.hiddenCategory)
+          (details.flags // toplevel.flags);
+      in optionalString (allVisibleOptions != {}) ''
         # Options
 
-        ${showOptions (details.flags // toplevel.flags)}
+        ${showOptions allVisibleOptions}
 
         > **Note**
         >
diff --git a/src/libutil/args.cc b/src/libutil/args.cc
index 8db293762..e410c7eec 100644
--- a/src/libutil/args.cc
+++ b/src/libutil/args.cc
@@ -236,7 +236,7 @@ nlohmann::json Args::toJSON()
 
     for (auto & [name, flag] : longFlags) {
         auto j = nlohmann::json::object();
-        if (hiddenCategories.count(flag->category)) continue;
+        j["hiddenCategory"] = hiddenCategories.count(flag->category) > 0;
         if (flag->aliases.count(name)) continue;
         if (flag->shortName)
             j["shortName"] = std::string(1, flag->shortName);