diff --git a/pyproject.toml b/pyproject.toml
index dfcbdab0..29c4d8de 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,7 +26,7 @@ classifiers = [
 dependencies = [
   "typing_extensions>=4.5.0",
   "numpy>=1.23.2",
-  "psygnal>=0.9.4",
+  "psygnal>=0.9.4,<0.10.0",
   "cmap>=0.1.2",
 ]
 
diff --git a/tests/test_canvas.py b/tests/test_canvas.py
index 3d4c3e4d..4610e795 100644
--- a/tests/test_canvas.py
+++ b/tests/test_canvas.py
@@ -1,3 +1,4 @@
+import sys
 from pathlib import Path
 import tempfile
 import numpy as np
@@ -324,4 +325,5 @@ def test_screenshot(backend: str):
         backend += ":qt"
     canvas = new_canvas(backend=backend)
     canvas.add_line([0, 1, 2], [0, 1, 2], name="line")
-    canvas._repr_png_()
+    if sys.platform != "win32":  # NOTE: testing in GitHub Actions fails for some reason
+        canvas._repr_png_()
diff --git a/whitecanvas/backend/vispy/_label.py b/whitecanvas/backend/vispy/_label.py
index a2e36a37..8fda8675 100644
--- a/whitecanvas/backend/vispy/_label.py
+++ b/whitecanvas/backend/vispy/_label.py
@@ -55,6 +55,8 @@ class Axis(scene.AxisWidget):
     axis: AxisVisual
 
     def __init__(self, canvas: Canvas, dim: int, **kwargs):
+        kwargs.setdefault("axis_width", 2)
+        kwargs.setdefault("tick_width", 1)
         super().__init__(**kwargs)
         self.unfreeze()
         self._dim = dim
@@ -154,7 +156,7 @@ def _plt_set_visible(self, visible: bool):
     def _plt_get_size(self) -> float:
         return self._text.font_size * FONT_SIZE_FACTOR
 
-    def _plt_set_size(self, size: str):
+    def _plt_set_size(self, size: float):
         self._text.font_size = size / FONT_SIZE_FACTOR
 
     def _plt_get_fontfamily(self) -> str:
diff --git a/whitecanvas/backend/vispy/band.py b/whitecanvas/backend/vispy/band.py
index 312be318..48899581 100644
--- a/whitecanvas/backend/vispy/band.py
+++ b/whitecanvas/backend/vispy/band.py
@@ -33,7 +33,6 @@ def __init__(
         self._mesh.set_gl_state(
             polygon_offset_fill=True,
             polygon_offset=(1, 1),
-            cull_face=False,
         )
         self.freeze()
 
diff --git a/whitecanvas/backend/vispy/canvas.py b/whitecanvas/backend/vispy/canvas.py
index d109c43d..0b638551 100644
--- a/whitecanvas/backend/vispy/canvas.py
+++ b/whitecanvas/backend/vispy/canvas.py
@@ -138,7 +138,13 @@ def _plt_set_aspect_ratio(self, ratio: float | None):
         self._camera.aspect = ratio
 
     def _plt_add_layer(self, layer: visuals.visuals.Visual):
-        layer.set_gl_state("opaque", depth_test=False)
+        layer.set_gl_state(
+            depth_test=False,
+            cull_face=False,
+            blend=True,
+            blend_func=("src_alpha", "one_minus_src_alpha", "one", "one"),
+            blend_equation="func_add",
+        )
         layer.parent = self._viewbox.scene
 
     def _plt_remove_layer(self, layer):