diff --git a/vlib/v/builder/builder.v b/vlib/v/builder/builder.v
index 06d5db4f39..65b4f1524e 100644
--- a/vlib/v/builder/builder.v
+++ b/vlib/v/builder/builder.v
@@ -31,7 +31,8 @@ pub mut:
 pub fn new_builder(pref &pref.Preferences) Builder {
 	rdir := os.real_path(pref.path)
 	compiled_dir := if os.is_dir(rdir) { rdir } else { os.dir(rdir) }
-	table := table.new_table()
+	mut table := table.new_table()
+	table.is_fmt = false
 	if pref.use_color == .always {
 		util.emanager.set_support_color(true)
 	}
diff --git a/vlib/v/fmt/tests/fntype_alias_keep.vv b/vlib/v/fmt/tests/fntype_alias_keep.vv
new file mode 100644
index 0000000000..57c582c7a4
--- /dev/null
+++ b/vlib/v/fmt/tests/fntype_alias_keep.vv
@@ -0,0 +1,65 @@
+module ui
+
+import gg
+import gx
+import eventbus
+
+pub type DrawFn = fn (ctx &gg.Context, state voidptr)
+
+pub type ClickFn = fn (e MouseEvent, func voidptr)
+
+pub type KeyFn = fn (e KeyEvent, func voidptr)
+
+pub type ScrollFn = fn (e ScrollEvent, func voidptr)
+
+pub type MouseMoveFn = fn (e MouseMoveEvent, func voidptr)
+
+[ref_only]
+pub struct Window {
+pub mut:
+	ui            &UI = voidptr(0)
+	children      []Widget
+	child_window  &Window = voidptr(0)
+	parent_window &Window = voidptr(0)
+	has_textbox   bool // for initial focus
+	tab_index     int
+	just_tabbed   bool
+	state         voidptr
+	draw_fn       DrawFn
+	title         string
+	mx            f64
+	my            f64
+	width         int
+	height        int
+	bg_color      gx.Color
+	click_fn      ClickFn
+	mouse_down_fn ClickFn
+	mouse_up_fn   ClickFn
+	scroll_fn     ScrollFn
+	key_down_fn   KeyFn
+	char_fn       KeyFn
+	mouse_move_fn MouseMoveFn
+	eventbus      &eventbus.EventBus = eventbus.new()
+}
+
+pub struct WindowConfig {
+pub:
+	width         int
+	height        int
+	resizable     bool
+	title         string
+	always_on_top bool
+	state         voidptr
+	draw_fn       DrawFn
+	bg_color      gx.Color = default_window_color
+	on_click      ClickFn
+	on_mouse_down ClickFn
+	on_mouse_up   ClickFn
+	on_key_down   KeyFn
+	on_scroll     ScrollFn
+	on_mouse_move MouseMoveFn
+	children      []Widget
+	font_path     string
+	// pub mut:
+	// parent_window &Window
+}
diff --git a/vlib/v/table/atypes.v b/vlib/v/table/atypes.v
index 446f8c4902..83928c9482 100644
--- a/vlib/v/table/atypes.v
+++ b/vlib/v/table/atypes.v
@@ -839,10 +839,12 @@ pub fn (table &Table) type_to_str(t Type) string {
 			}
 		}
 		.function {
-			info := sym.info as FnType
-			res = table.fn_signature(info.func, {
-				type_only: true
-			})
+			if !table.is_fmt {
+				info := sym.info as FnType
+				res = table.fn_signature(info.func, {
+					type_only: true
+				})
+			}
 		}
 		.map {
 			if int(t) == map_type_idx {
diff --git a/vlib/v/table/table.v b/vlib/v/table/table.v
index c94bf0e878..9af62367f4 100644
--- a/vlib/v/table/table.v
+++ b/vlib/v/table/table.v
@@ -18,6 +18,7 @@ pub mut:
 	redefined_fns []string
 	fn_gen_types  map[string][]Type // for generic functions
 	cmod_prefix   string // needed for table.type_to_str(Type) while vfmt; contains `os.`
+	is_fmt        bool
 }
 
 pub struct Fn {
@@ -83,6 +84,7 @@ mut:
 pub fn new_table() &Table {
 	mut t := &Table{}
 	t.register_builtin_type_symbols()
+	t.is_fmt = true
 	return t
 }