1 files changed, 8 insertions, 3 deletions
diff --git a/test/gtk/util.py b/test/gtk/util.py
index 9ecd50ece..06a949c5e 100644
--- a/test/gtk/util.py
+++ b/test/gtk/util.py
@@ -3,12 +3,15 @@ from pathlib import Path
 from gi.repository import Gdk
 from gi.repository import Gtk
 
+from gajim.common.const import CSSPriority
 
-def get_gajim_dir():
+
+def get_gajim_dir() -> Path:
     gajim_path = Path(__file__) / '..' / '..' / '..' / 'gajim'
     return gajim_path.resolve()
 
-def load_style(filename, priority):
+
+def load_style(filename: str, priority: CSSPriority) -> None:
     path = get_gajim_dir() / 'data' / 'style' / filename
     try:
         with open(str(path), 'r', encoding='utf8') as file:
@@ -18,6 +21,8 @@ def load_style(filename, priority):
         return
     provider = Gtk.CssProvider()
     provider.load_from_data(bytes(css.encode('utf-8')))
-    Gtk.StyleContext.add_provider_for_screen(Gdk.Screen.get_default(),
+    screen = Gdk.Screen.get_default()
+    assert screen is not None
+    Gtk.StyleContext.add_provider_for_screen(screen,
                                              provider,
                                              priority)