diff --git a/novelwriter/extensions/modified.py b/novelwriter/extensions/modified.py
index 7e245d21..b802a4d9 100644
--- a/novelwriter/extensions/modified.py
+++ b/novelwriter/extensions/modified.py
@@ -217,12 +217,6 @@ class NPushButton(QPushButton):
         if icon:
             self.refreshIcon()
 
-    def setThemeIcon(self, icon: str, color: str | None = None) -> None:
-        """Set an icon from the current theme."""
-        self._icon = icon
-        self._color = color
-        self.refreshIcon()
-
     def refreshIcon(self) -> None:
         """Reload the theme icon."""
         if self._icon:
diff --git a/novelwriter/shared.py b/novelwriter/shared.py
index be439b48..b76ad165 100644
--- a/novelwriter/shared.py
+++ b/novelwriter/shared.py
@@ -34,7 +34,7 @@ from typing import TYPE_CHECKING, TypeVar
 
 from PyQt6.QtCore import QObject, QRunnable, QThreadPool, QTimer, QUrl, pyqtSignal, pyqtSlot
 from PyQt6.QtGui import QDesktopServices, QFont, QScreen
-from PyQt6.QtWidgets import QApplication, QDialog, QFileDialog, QFontDialog, QMessageBox, QWidget
+from PyQt6.QtWidgets import QApplication, QFileDialog, QFontDialog, QMessageBox, QWidget
 
 from novelwriter.common import formatFileFilter
 from novelwriter.constants import nwFiles
@@ -536,4 +536,4 @@ class _GuiAlert(QMessageBox):
     def _onReject(self) -> None:
         """Process rejected state."""
         self._state = False
-        self.setResult(QDialog.DialogCode.Rejected)
+        self.close()
diff --git a/run_tests.py b/run_tests.py
index 18e1eeae..6f593127 100755
--- a/run_tests.py
+++ b/run_tests.py
@@ -25,7 +25,10 @@ if __name__ == "__main__":
     env["QT_SCALE_FACTOR"] = "1.0"
 
     if args.r or args.t or args.u:
-        cmd = ["coverage", "run", "-m"]
+        cmd = ["coverage", "run"]
+        if args.lf or args.sw:
+            cmd += ["--append"]
+        cmd += ["-m"]
     else:
         cmd = [sys.executable, "-m"]
 
diff --git a/tests/conftest.py b/tests/conftest.py
index 765755bf..f8e3a5eb 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -157,9 +157,11 @@ def projPath(fncPath):
 def mockGUI(qtbot, monkeypatch):
     """Create a mock instance of novelWriter's main GUI class."""
     from novelwriter.gui.theme import GuiTheme
+    from novelwriter.shared import _GuiAlert
 
     monkeypatch.setattr(QMessageBox, "exec", lambda *a: None)
-    monkeypatch.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.Yes)
+    monkeypatch.setattr(_GuiAlert, "exec", lambda *a: None)
+    monkeypatch.setattr(_GuiAlert, "finalState", True)
     gui = MockGuiMain()
     theme = GuiTheme()
     monkeypatch.setattr(SHARED, "_gui", gui)
@@ -182,9 +184,11 @@ def nwGUI(qtbot, monkeypatch, functionFixture):
     """Create an instance of the novelWriter GUI."""
     from novelwriter.gui.theme import GuiTheme
     from novelwriter.guimain import GuiMain
+    from novelwriter.shared import _GuiAlert
 
     monkeypatch.setattr(QMessageBox, "exec", lambda *a: None)
-    monkeypatch.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.Yes)
+    monkeypatch.setattr(_GuiAlert, "exec", lambda *a: None)
+    monkeypatch.setattr(_GuiAlert, "finalState", True)
 
     CONFIG.loadConfig()
     SHARED.initTheme(GuiTheme())
diff --git a/tests/mocked.py b/tests/mocked.py
index f86d5be0..92b56abe 100644
--- a/tests/mocked.py
+++ b/tests/mocked.py
@@ -22,9 +22,12 @@ from __future__ import annotations
 
 from unittest.mock import MagicMock
 
+from PyQt6.QtCore import QSize
 from PyQt6.QtGui import QFont, QIcon, QPixmap
 from PyQt6.QtWidgets import QWidget
 
+from novelwriter.extensions.modified import NPushButton
+
 
 class MockGuiMain(QWidget):
 
@@ -72,6 +75,9 @@ class MockTheme:
     def getHeaderDecoration(self, *a) -> QPixmap:
         return QPixmap()
 
+    def getStandardButton(self, *a) -> NPushButton:
+        return NPushButton(None, "", QSize(1, 1))  # type: ignore
+
     def getIcon(self, *a) -> QIcon:
         return QIcon()
 
diff --git a/tests/test_base/test_base_shared.py b/tests/test_base/test_base_shared.py
index 64cc306b..a020a694 100644
--- a/tests/test_base/test_base_shared.py
+++ b/tests/test_base/test_base_shared.py
@@ -26,10 +26,10 @@ import pytest
 
 from PyQt6.QtCore import QUrl
 from PyQt6.QtGui import QDesktopServices
-from PyQt6.QtWidgets import QFileDialog, QMessageBox, QWidget
+from PyQt6.QtWidgets import QFileDialog, QWidget
 
 from novelwriter.core.project import NWProject
-from novelwriter.shared import SharedData
+from novelwriter.shared import SharedData, _GuiAlert
 
 from tests.mocked import MockGuiMain, MockTheme
 from tests.tools import buildTestProject
@@ -143,10 +143,10 @@ def testBaseSharedData_Projects(monkeypatch, caplog, fncPath):
 
 
 @pytest.mark.base
-def testBaseSharedData_Alerts(qtbot, monkeypatch, caplog):
+def testBaseSharedData_Alerts(qtbot, monkeypatch, caplog, mockGUI):
     """Test SharedData class alert helper functions."""
-    monkeypatch.setattr(QMessageBox, "exec", lambda *a: None)
-    monkeypatch.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.Yes)
+    monkeypatch.setattr(_GuiAlert, "exec", lambda *a: None)
+    monkeypatch.setattr(_GuiAlert, "finalState", True)
 
     shared = SharedData()
 
@@ -188,3 +188,63 @@ def testBaseSharedData_Alerts(qtbot, monkeypatch, caplog):
     # Question box
     assert shared.question("Why?") is True
     assert shared.lastAlert == "Why?"
+
+
+@pytest.mark.base
+def testBaseSharedData_GuiAlert():
+    """Test the _GuiAlert class."""
+    alert = _GuiAlert(None, MockTheme())  # type: ignore
+
+    # Default states
+    assert alert.logMessage == ""
+    assert alert.finalState is False
+
+    # Populate message
+    text = "one"
+    info = "two"
+    details = "three"
+    alert.setMessage(text, info, details)
+    assert alert.logMessage == f"{text} {info} {details}"
+    assert alert.text() == text
+    assert alert.informativeText() == info
+    assert alert.detailedText() == details
+
+    # Populate exception
+    exc = Exception("oops")
+    alert.setException(exc)
+    assert alert.logMessage == f"{text} {info} {details}"
+    assert alert.informativeText() == f"{info}<br><b>Exception</b>: {exc!s}"
+
+    # Alert: Info
+    alert.setAlertType(_GuiAlert.INFO, False)
+    assert hasattr(alert, "_btnOk")
+    assert alert.windowTitle() == "Information"
+    alert._btnOk.click()
+    assert alert.finalState is True
+    alert._state = False
+
+    # Alert: Warning
+    alert.setAlertType(_GuiAlert.WARN, False)
+    assert hasattr(alert, "_btnOk")
+    assert alert.windowTitle() == "Warning"
+    alert._btnOk.click()
+    assert alert.finalState is True
+    alert._state = False
+
+    # Alert: Error
+    alert.setAlertType(_GuiAlert.ERROR, False)
+    assert hasattr(alert, "_btnOk")
+    assert alert.windowTitle() == "Error"
+    alert._btnOk.click()
+    assert alert.finalState is True
+    alert._state = False
+
+    # Alert: Question
+    alert.setAlertType(_GuiAlert.ASK, True)
+    assert hasattr(alert, "_btnYes")
+    assert hasattr(alert, "_btnNo")
+    assert alert.windowTitle() == "Question"
+    alert._btnYes.click()
+    assert alert.finalState is True
+    alert._btnNo.click()
+    assert alert.finalState is False
diff --git a/tests/test_core/test_core_project.py b/tests/test_core/test_core_project.py
index cdb202c1..799cd423 100644
--- a/tests/test_core/test_core_project.py
+++ b/tests/test_core/test_core_project.py
@@ -25,13 +25,12 @@ from zipfile import ZipFile
 
 import pytest
 
-from PyQt6.QtWidgets import QMessageBox
-
 from novelwriter import CONFIG, SHARED
 from novelwriter.constants import nwFiles
 from novelwriter.core.project import NWProject, NWProjectState
 from novelwriter.core.projectxml import ProjectXMLReader, ProjectXMLWriter, XMLReadState
 from novelwriter.enum import nwItemClass
+from novelwriter.shared import _GuiAlert
 
 from tests.mocked import causeOSError
 from tests.tools import XML_IGNORE, C, buildTestProject, cmpFiles
@@ -274,14 +273,14 @@ def testCoreProject_Open(monkeypatch, caplog, mockGUI, fncPath, mockRnd):
     # Won't convert legacy file
     with monkeypatch.context() as mp:
         mp.setattr(ProjectXMLReader, "state", property(lambda *a: XMLReadState.WAS_LEGACY))
-        mp.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.No)
+        mp.setattr(_GuiAlert, "finalState", False)
         assert project.openProject(fncPath, clearLock=True) is False
         assert "The file format of your project is about to be" in SHARED.lastAlert
 
     # Won't open project from newer version
     with monkeypatch.context() as mp:
         mp.setattr(ProjectXMLReader, "hexVersion", property(lambda *a: 0x99999999))
-        mp.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.No)
+        mp.setattr(_GuiAlert, "finalState", False)
         assert project.openProject(fncPath, clearLock=True) is False
         assert "This project was saved by a newer version" in SHARED.lastAlert
 
diff --git a/tests/test_gui/test_gui_guimain.py b/tests/test_gui/test_gui_guimain.py
index 0e15b71e..4cfa3a91 100644
--- a/tests/test_gui/test_gui_guimain.py
+++ b/tests/test_gui/test_gui_guimain.py
@@ -30,7 +30,7 @@ import pytest
 
 from PyQt6.QtCore import Qt
 from PyQt6.QtGui import QPalette
-from PyQt6.QtWidgets import QInputDialog, QMessageBox
+from PyQt6.QtWidgets import QInputDialog
 
 from novelwriter import CONFIG, SHARED, __hexversion__
 from novelwriter.common import jsonEncode
@@ -42,6 +42,7 @@ from novelwriter.gui.doceditor import GuiDocEditor
 from novelwriter.gui.noveltree import GuiNovelView
 from novelwriter.gui.outline import GuiOutlineView
 from novelwriter.gui.projtree import GuiProjectTree
+from novelwriter.shared import _GuiAlert
 from novelwriter.tools.welcome import GuiWelcome
 from novelwriter.types import QtModCtrl, QtModShift
 
@@ -104,7 +105,7 @@ def testGuiMain_Launch(qtbot, monkeypatch, nwGUI, projPath):
 
     # Check that closes can be blocked
     with monkeypatch.context() as mp:
-        mp.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.No)
+        mp.setattr(_GuiAlert, "finalState", False)
         assert nwGUI.openProject(projPath) is True
         assert nwGUI.closeMain() is False
     nwGUI.closeProject()
@@ -841,7 +842,7 @@ def testGuiMain_OpenClose(qtbot, monkeypatch, nwGUI, projPath, fncPath, mockRnd)
     # Block closing
     assert SHARED.hasProject is True
     with monkeypatch.context() as mp:
-        mp.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.No)
+        mp.setattr(_GuiAlert, "finalState", False)
         assert nwGUI.openProject(projPath) is False
         assert SHARED.hasProject is True
 
@@ -854,7 +855,7 @@ def testGuiMain_OpenClose(qtbot, monkeypatch, nwGUI, projPath, fncPath, mockRnd)
     shutil.copyfile(lockBack, lockPath)
 
     with monkeypatch.context() as mp:
-        mp.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.No)
+        mp.setattr(_GuiAlert, "finalState", False)
         assert nwGUI.openProject(projPath) is False
 
     assert nwGUI.openProject(projPath) is True
diff --git a/tests/test_gui/test_gui_i18n.py b/tests/test_gui/test_gui_i18n.py
index 915d83a4..e482d85f 100644
--- a/tests/test_gui/test_gui_i18n.py
+++ b/tests/test_gui/test_gui_i18n.py
@@ -24,7 +24,7 @@ import sys
 
 import pytest
 
-from PyQt6.QtWidgets import QApplication, QDialog, QMessageBox
+from PyQt6.QtWidgets import QApplication, QDialog
 
 from novelwriter import CONFIG, SHARED
 from novelwriter.dialogs.about import GuiAbout
@@ -49,8 +49,6 @@ LANG_DATA = CONFIG.listLanguages(CONFIG.LANG_NW)
 def testGuiI18n_Localisation(qtbot, monkeypatch, language, nwGUI, projPath):
     """Test loading the gui with a specific language."""
     monkeypatch.setattr(QDialog, "exec", lambda *a: None)
-    monkeypatch.setattr(QMessageBox, "exec", lambda *a: None)
-    monkeypatch.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.Yes)
 
     # Set the test language
     CONFIG.guiLocale = language
diff --git a/tests/test_gui/test_gui_mainmenu.py b/tests/test_gui/test_gui_mainmenu.py
index 0d6344bc..e599e9f9 100644
--- a/tests/test_gui/test_gui_mainmenu.py
+++ b/tests/test_gui/test_gui_mainmenu.py
@@ -25,12 +25,13 @@ from unittest.mock import MagicMock
 import pytest
 
 from PyQt6.QtGui import QAction, QDesktopServices, QTextBlock
-from PyQt6.QtWidgets import QFileDialog, QMessageBox
+from PyQt6.QtWidgets import QFileDialog
 
 from novelwriter import CONFIG, SHARED
 from novelwriter.constants import nwKeyWords, nwShortcode, nwStats, nwUnicode
 from novelwriter.enum import nwDocAction, nwDocInsert
 from novelwriter.gui.doceditor import GuiDocEditor
+from novelwriter.shared import _GuiAlert
 from novelwriter.types import QtKeepAnchor, QtMoveRight, QtSelectWord
 
 from tests.tools import C, buildTestProject, writeFile
@@ -575,7 +576,7 @@ def testGuiMainMenu_Insert(qtbot, monkeypatch, nwGUI, fncPath, projPath, mockRnd
 
     # The document isn't empty, so the message box should pop
     with monkeypatch.context() as mp:
-        mp.setattr(QMessageBox, "result", lambda *a, **k: QMessageBox.StandardButton.No)
+        mp.setattr(_GuiAlert, "finalState", False)
         assert not nwGUI.importDocument()
         assert docEditor.getText() == "Bar"
 
diff --git a/tests/test_gui/test_gui_projtree.py b/tests/test_gui/test_gui_projtree.py
index f6430f55..bdd50ad0 100644
--- a/tests/test_gui/test_gui_projtree.py
+++ b/tests/test_gui/test_gui_projtree.py
@@ -26,7 +26,7 @@ import pytest
 
 from PyQt6.QtCore import QEvent, QItemSelectionModel, QModelIndex, QPointF
 from PyQt6.QtGui import QMouseEvent
-from PyQt6.QtWidgets import QMenu, QMessageBox
+from PyQt6.QtWidgets import QMenu
 
 from novelwriter import CONFIG, SHARED
 from novelwriter.dialogs.docmerge import GuiDocMerge
@@ -34,6 +34,7 @@ from novelwriter.dialogs.docsplit import GuiDocSplit
 from novelwriter.dialogs.editlabel import GuiEditLabel
 from novelwriter.enum import nwDocMode, nwItemClass, nwItemLayout, nwItemType
 from novelwriter.gui.projtree import _TreeContextMenu
+from novelwriter.shared import _GuiAlert
 from novelwriter.types import (
     QtAccepted, QtModNone, QtMouseLeft, QtMouseMiddle, QtRejected,
     QtScrollAlwaysOff, QtScrollAsNeeded
@@ -627,7 +628,7 @@ def testGuiProjTree_DeleteRequest(qtbot, caplog, monkeypatch, nwGUI, projPath, m
 
     # User can cancel move to trash
     with monkeypatch.context() as mp:
-        mp.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.No)
+        mp.setattr(_GuiAlert, "finalState", False)
         projTree.processDeleteRequest(hScenes, askFirst=True)
     assert [n.item.itemName for n in tree.model.root.allChildren()] == [
         "Novel", "Title Page", "New Folder", "New Chapter", "New Scene",
@@ -645,7 +646,7 @@ def testGuiProjTree_DeleteRequest(qtbot, caplog, monkeypatch, nwGUI, projPath, m
 
     # User can block permanent deletion
     with monkeypatch.context() as mp:
-        mp.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.No)
+        mp.setattr(_GuiAlert, "finalState", False)
         projTree.processDeleteRequest(hScenes[0:2], askFirst=True)
     assert [n.item.itemName for n in tree.model.root.allChildren()] == [
         "Novel", "Title Page", "New Folder", "New Chapter", "New Scene",
@@ -677,7 +678,7 @@ def testGuiProjTree_DeleteRequest(qtbot, caplog, monkeypatch, nwGUI, projPath, m
 
     # Trash can be completely emptied, but user can block it
     with monkeypatch.context() as mp:
-        mp.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.No)
+        mp.setattr(_GuiAlert, "finalState", False)
         projTree.emptyTrash()
     assert [n.item.itemName for n in tree.model.root.allChildren()] == [
         "Novel", "Title Page", "Chapter Folder", "Plot", "Characters", "Trash",
@@ -995,7 +996,7 @@ def testGuiProjTree_Duplicate(qtbot, monkeypatch, nwGUI, projPath, mockRnd):
 
     # Duplicate title page, but select no
     with monkeypatch.context() as mp:
-        mp.setattr(QMessageBox, "result", lambda *a: QtRejected)
+        mp.setattr(_GuiAlert, "finalState", False)
         projTree.duplicateFromHandle(C.hTitlePage)
     assert [n.item.itemName for n in tree.model.root.allChildren()] == [
         "Novel", "Title Page", "New Folder", "New Chapter", "New Scene",
@@ -1302,7 +1303,7 @@ def testGuiProjTree_ContextMenu(qtbot, monkeypatch, nwGUI, projPath, mockRnd):
 
     # Click no on the dialog
     with monkeypatch.context() as mp:
-        mp.setattr(QMessageBox, "result", lambda *a: QtRejected)
+        mp.setattr(_GuiAlert, "finalState", False)
         ctxMenu._convertFolderToFile(nwItemLayout.DOCUMENT)
         assert nodeOne.item.isFolderType()
 
diff --git a/tests/test_tools/test_tools_manusbuild.py b/tests/test_tools/test_tools_manusbuild.py
index 91924120..35ddb7fa 100644
--- a/tests/test_tools/test_tools_manusbuild.py
+++ b/tests/test_tools/test_tools_manusbuild.py
@@ -26,13 +26,14 @@ import pytest
 
 from PyQt6.QtCore import QUrl
 from PyQt6.QtGui import QDesktopServices
-from PyQt6.QtWidgets import QFileDialog, QListWidgetItem, QMessageBox
+from PyQt6.QtWidgets import QFileDialog, QListWidgetItem
 from pytestqt.qtbot import QtBot
 
 from novelwriter.constants import nwLabels
 from novelwriter.core.buildsettings import BuildSettings
 from novelwriter.enum import nwBuildFmt
 from novelwriter.guimain import GuiMain
+from novelwriter.shared import _GuiAlert
 from novelwriter.tools.manusbuild import GuiManuscriptBuild
 from novelwriter.types import QtDialogClose
 
@@ -134,7 +135,7 @@ def testToolManuscriptBuild_Main(
     manus.buildPath.setText(str(fncPath))
     manus.buildName.setText("TestBuild")
     with monkeypatch.context() as mp:
-        mp.setattr(QMessageBox, "result", lambda *a: QMessageBox.StandardButton.No)
+        mp.setattr(_GuiAlert, "finalState", False)
         assert manus._runBuild() is False
 
     # Test that the open button works