diff --git a/scripts/wk/ui/tui.py b/scripts/wk/ui/tui.py
index cb07cd85..80960ea8 100644
--- a/scripts/wk/ui/tui.py
+++ b/scripts/wk/ui/tui.py
@@ -35,7 +35,7 @@ class TUI():
     self.side_width: int = TMUX_SIDE_WIDTH
     self.title_text: str = title_text if title_text else 'Title Text'
     self.title_text_line2: str = ''
-    self.title_colors: list[str | None] = ['BLUE', None]
+    self.title_colors: list[str] = ['BLUE', '']
 
     # Init tmux and start a background process to maintain layout
     self.init_tmux()
@@ -47,7 +47,7 @@ class TUI():
   def add_info_pane(
       self,
       lines: int | None = None,
-      percent: int | None = None,
+      percent: int = 0,
       update_layout: bool = True,
       **tmux_args,
       ) -> None:
@@ -117,7 +117,7 @@ class TUI():
   def add_worker_pane(
       self,
       lines: int | None = None,
-      percent: int | None = None,
+      percent: int = 0,
       update_layout: bool = True,
       **tmux_args,
       ) -> None:
@@ -136,7 +136,7 @@ class TUI():
     tmux_args.update({
       'behind': False,
       'lines': lines,
-      'percent': percent,
+      'percent': percent if percent else None,
       'target_id': None,
       'vertical': True,
       })