diff --git a/contrib/flake.nix b/contrib/flake.nix
index a75e584075..86e4b37cfa 100644
--- a/contrib/flake.nix
+++ b/contrib/flake.nix
@@ -44,7 +44,7 @@
         pythonEnv = legacyPkgs.python3;
         luacheck = legacyPkgs.luaPackages.luacheck;
       in
-        neovim-debug.overrideAttrs(oa: {
+        (neovim-debug.override({doCheck = true;})).overrideAttrs(oa: {
           cmakeFlags = oa.cmakeFlags ++ [
             "-DLUACHECK_PRG=${luacheck}/bin/luacheck"
             "-DMIN_LOG_LEVEL=0"
diff --git a/test/functional/ui/searchhl_spec.lua b/test/functional/ui/searchhl_spec.lua
index 3bb72303bf..740126df31 100644
--- a/test/functional/ui/searchhl_spec.lua
+++ b/test/functional/ui/searchhl_spec.lua
@@ -480,6 +480,11 @@ describe('search highlighting', function()
       {4:search hit BOTTOM, continuing at TOP}    |
     ]])
 
+    -- check hilights work also in folds
+    feed("zf4j")
+    command("%foldopen")
+    screen:expect_unchanged()
+
     feed_command("call clearmatches()")
     screen:expect([[
         very spec{2:^ial te}xt                     |