diff --git a/.github/workflows/test_napari_repo.yml b/.github/workflows/test_napari_repo.yml
index 18a3e62e3..1270132d2 100644
--- a/.github/workflows/test_napari_repo.yml
+++ b/.github/workflows/test_napari_repo.yml
@@ -34,7 +34,7 @@ jobs:
       fail-fast: false
       matrix:
         platform: [ ubuntu-24.04 ]
-        python: ['3.10', '3.11', '3.12']
+        python: ['3.10', '3.11', '3.12', '3.13']
         napari_version: ['repo']
     steps:
       - uses: actions/checkout@v6
diff --git a/package/PartSeg/common_gui/main_window.py b/package/PartSeg/common_gui/main_window.py
index 6f5ba861b..b7e15d586 100644
--- a/package/PartSeg/common_gui/main_window.py
+++ b/package/PartSeg/common_gui/main_window.py
@@ -227,10 +227,13 @@ def get_colormaps(self) -> list[Optional[colormap.Colormap]]:
         return [self.settings.colormap_dict[name][0] for name in colormaps_name]
 
     def napari_viewer_show(self):
-        viewer = Viewer(title="Additional output", settings=self.settings, partseg_viewer_name=self.channel_info)
+        viewer = Viewer(
+            title="Additional output", settings=self.settings, partseg_viewer_name=self.channel_info, show=False
+        )
         viewer.scale_bar.unit = "nm"
         viewer.theme = self.settings.theme_name
         viewer.create_initial_layers(image=True, roi=True, additional_layers=False, points=True)
+        viewer.show()
         self.viewer_list.append(viewer)
         viewer.window.qt_viewer.destroyed.connect(lambda _x: self.close_viewer(viewer))
 
diff --git a/tox.ini b/tox.ini
index b8651056d..5660717bd 100644
--- a/tox.ini
+++ b/tox.ini
@@ -71,15 +71,23 @@ deps=
     pytest-json-report
     lxml_html_clean
 
-[testenv:py{39,310,311,312,313}-{PyQt5,PySide2,PyQt6,PySide6}-napari_{419,54,repo}]
+
+[testenv:py{39,310,311,312,313}-{PyQt5,PySide2,PyQt6,PySide6}-napari_{419,54}]
 deps =
     {[testenv]deps}
     napari_419: napari==0.4.19.post1
     napari_54: napari==0.5.4
-    napari_repo: git+https://github.com/napari/napari.git
 commands =
-    !napari_repo: python -m pytest -v package/tests/test_PartSeg/test_napari_widgets.py --json-report --json-report-file={toxinidir}/report-{envname}-{sys_platform}.json {posargs}
-    napari_repo: python -m pytest package/tests --json-report --json-report-file={toxinidir}/report-{envname}-{sys_platform}.json {posargs}
+    python -m pytest -v package/tests/test_PartSeg/test_napari_widgets.py --json-report --json-report-file={toxinidir}/report-{envname}-{sys_platform}.json {posargs}
+
+
+[testenv:py{310,311,312,313}-{PyQt5,PyQt6,PySide6}-napari_repo]
+deps =
+    {[testenv]deps}
+    git+https://github.com/napari/napari.git
+commands =
+    python -m pytest package/tests --json-report --json-report-file={toxinidir}/report-{envname}-{sys_platform}.json {posargs}
+
 
 [testenv:py{39,310,311,312,313}-PyQt5-coverage]
 deps =