diff --git a/novelwriter/tools/manuscript.py b/novelwriter/tools/manuscript.py
index b2344aacd..762767cc4 100644
--- a/novelwriter/tools/manuscript.py
+++ b/novelwriter/tools/manuscript.py
@@ -32,11 +32,11 @@
 
 from PyQt5.QtGui import QColor, QCursor, QFont, QPalette, QResizeEvent
 from PyQt5.QtCore import QSize, QTimer, Qt, pyqtSlot
-from PyQt5.QtPrintSupport import QPrintPreviewDialog, QPrinter
 from PyQt5.QtWidgets import (
     QDialog, QGridLayout, QHBoxLayout, QLabel, QListWidget, QListWidgetItem, QPushButton,
     QSplitter, QTextBrowser, QToolButton, QVBoxLayout, QWidget, qApp
 )
+from PyQt5.QtPrintSupport import QPrintPreviewDialog, QPrinter
 
 from novelwriter import CONFIG
 from novelwriter.error import logException
@@ -300,7 +300,6 @@ def _generatePreview(self):
         for step, _ in docBuild.iterBuildHTML(None):
             self.docPreview.buildStep(step + 1)
             qApp.processEvents()
-            qApp.thread().msleep(5)
 
         buildObj = docBuild.lastBuild
         assert isinstance(buildObj, ToHtml)
@@ -528,10 +527,11 @@ def setJustify(self, state: bool):
 
     def setTextFont(self, family: str, size: int):
         """Set the text font properties."""
-        font = QFont()
-        font.setFamily(family)
-        font.setPointSize(size)
-        self.setFont(font)
+        if family:
+            font = QFont()
+            font.setFamily(family)
+            font.setPointSize(size)
+            self.setFont(font)
         return
 
     ##
@@ -617,6 +617,7 @@ def printPreview(self, printer: QPrinter):
         self.document().print(printer)
         qApp.restoreOverrideCursor()
         return
+
     ##
     #  Private Slots
     ##
diff --git a/tests/test_tools/test_tools_manuscript.py b/tests/test_tools/test_tools_manuscript.py
new file mode 100644
index 000000000..a57316576
--- /dev/null
+++ b/tests/test_tools/test_tools_manuscript.py
@@ -0,0 +1,242 @@
+"""
+novelWriter – Manuscript Tool Tester
+====================================
+
+This file is a part of novelWriter
+Copyright 2018–2023, Veronica Berglyd Olsen
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <https://www.gnu.org/licenses/>.
+"""
+
+import pytest
+
+from pathlib import Path
+from pytestqt.qtbot import QtBot
+
+from tools import C, buildTestProject, getGuiItem
+from mocked import causeOSError
+
+from PyQt5.QtCore import Qt, pyqtSlot
+from PyQt5.QtWidgets import QDialogButtonBox
+from PyQt5.QtPrintSupport import QPrintPreviewDialog
+
+from novelwriter import CONFIG
+from novelwriter.guimain import GuiMain
+from novelwriter.core.buildsettings import BuildSettings
+from novelwriter.tools.manuscript import GuiManuscript
+from novelwriter.tools.manusbuild import GuiManuscriptBuild
+from novelwriter.tools.manussettings import GuiBuildSettings
+
+
+@pytest.mark.gui
+def testManuscript_Init(monkeypatch, qtbot: QtBot, nwGUI: GuiMain, projPath: Path, mockRnd):
+    """Test the init/main functionality of the GuiManuscript dialog."""
+    buildTestProject(nwGUI, projPath)
+    nwGUI.openProject(projPath)
+    nwGUI.theProject.storage.getDocument(C.hChapterDoc).writeDocument("## A Chapter\n\n\t\tHi")
+    allText = "New Novel\nBy Jane Doe\nA Chapter\n\t\tHi\n* * *"
+
+    manus = GuiManuscript(nwGUI)
+    manus.show()
+    manus.loadContent()
+    assert manus.docPreview.toPlainText().strip() == ""
+
+    # Run the default build
+    manus.buildList.clearSelection()
+    manus.buildList.setCurrentRow(0)
+    with qtbot.waitSignal(manus.docPreview.document().contentsChanged):
+        manus.btnPreview.click()
+    assert manus.docPreview.toPlainText().strip() == allText
+
+    manus.close()
+
+    # A new dialog should load the old build
+    manus = GuiManuscript(nwGUI)
+    manus.show()
+    manus.loadContent()
+    assert manus.docPreview.toPlainText().strip() == allText
+    manus.close()
+
+    # But blocking the reload should leave it empty
+    with monkeypatch.context() as mp:
+        mp.setattr("builtins.open", lambda *a, **k: causeOSError)
+        manus = GuiManuscript(nwGUI)
+        manus.show()
+        manus.loadContent()
+        assert manus.docPreview.toPlainText().strip() == ""
+        manus.close()
+
+    # Finish
+    # qtbot.stop()
+
+# END Test testManuscript_Init
+
+
+@pytest.mark.gui
+def testManuscript_Builds(qtbot: QtBot, nwGUI: GuiMain, projPath: Path):
+    """Test the handling of builds in the GuiManuscript dialog."""
+    buildTestProject(nwGUI, projPath)
+    nwGUI.openProject(projPath)
+
+    manus = GuiManuscript(nwGUI)
+    manus.show()
+    manus.loadContent()
+
+    # Delete the default build
+    manus.buildList.clearSelection()
+    manus.buildList.setCurrentRow(0)
+    manus.tbDel.click()
+    assert manus.buildList.count() == 0
+
+    # Create a new build
+    manus.tbAdd.click()
+    bSettings = getGuiItem("GuiBuildSettings")
+    assert isinstance(bSettings, GuiBuildSettings)
+    bSettings.editBuildName.setText("Test Build")
+    build = None
+
+    @pyqtSlot(BuildSettings)
+    def _testNewSettingsReady(new: BuildSettings):
+        nonlocal build
+        build = new
+
+    with qtbot.waitSignal(bSettings.newSettingsReady, timeout=5000):
+        bSettings.newSettingsReady.connect(_testNewSettingsReady)
+        bSettings.dlgButtons.button(QDialogButtonBox.Save).click()
+
+    assert isinstance(build, BuildSettings)
+    assert build.name == "Test Build"
+    assert manus.buildList.count() == 1
+
+    # Edit the new build
+    manus.buildList.clearSelection()
+    manus.buildList.setCurrentRow(0)
+    manus.tbEdit.click()
+
+    bSettings = getGuiItem("GuiBuildSettings")
+    assert isinstance(bSettings, GuiBuildSettings)
+    build = None
+
+    with qtbot.waitSignal(bSettings.newSettingsReady, timeout=5000):
+        bSettings.newSettingsReady.connect(_testNewSettingsReady)
+        bSettings.dlgButtons.button(QDialogButtonBox.Apply).click()  # Should leave the dialog open
+
+    assert isinstance(build, BuildSettings)
+    assert build.name == "Test Build"
+    assert manus.buildList.count() == 1
+
+    # Close the dialog should also close the child dialogs
+    manus.btnClose.click()
+    if isinstance(bSettings, GuiBuildSettings):
+        # May have been garbage collected, but if it isn't, it should be hidden
+        assert bSettings.isVisible() is False
+
+    # Finish
+    # qtbot.stop()
+
+# END Test testManuscript_Builds
+
+
+@pytest.mark.gui
+def testManuscript_Features(monkeypatch, qtbot: QtBot, nwGUI: GuiMain, projPath: Path):
+    """Test other featurs of the GuiManuscript dialog."""
+    buildTestProject(nwGUI, projPath)
+    nwGUI.openProject(projPath)
+
+    manus = GuiManuscript(nwGUI)
+    manus.show()
+    manus.loadContent()
+
+    cacheFile = CONFIG.dataPath("cache") / f"build_{nwGUI.theProject.data.uuid}.json"
+    manus.buildList.setCurrentRow(0)
+    build = manus._getSelectedBuild()
+    assert isinstance(build, BuildSettings)
+
+    # Previews
+    # ========
+
+    # No build selected
+    manus.buildList.clearSelection()
+    manus.btnPreview.click()
+    qtbot.wait(200)  # Should be enough to run the build
+    assert manus.docPreview.toPlainText().strip() == ""
+    assert cacheFile.exists() is False
+
+    # Preview the first, but fail to save cache
+    manus.buildList.setCurrentRow(0)
+    with monkeypatch.context() as mp:
+        mp.setattr("builtins.open", lambda *a, **k: causeOSError)
+        with qtbot.waitSignal(manus.docPreview.document().contentsChanged):
+            manus.btnPreview.click()
+        assert cacheFile.exists() is False
+
+    # Preview again, and allow cache file to be created
+    manus.buildList.setCurrentRow(0)
+    with qtbot.waitSignal(manus.docPreview.document().contentsChanged):
+        manus.btnPreview.click()
+    assert manus.docPreview.toPlainText().strip() != ""
+    assert cacheFile.exists() is True
+
+    # Toggle justify
+    assert manus.docPreview.document().defaultTextOption().alignment() == Qt.AlignAbsolute
+    manus.docPreview.setJustify(True)
+    assert manus.docPreview.document().defaultTextOption().alignment() == Qt.AlignJustify
+    manus.docPreview.setJustify(False)
+    assert manus.docPreview.document().defaultTextOption().alignment() == Qt.AlignAbsolute
+
+    # Tests are too fast to trigger this one, so we trigger it manually to ensure it isn't failing
+    manus.docPreview._hideProgress()
+
+    # Builds
+    # ======
+
+    build._changed = True
+    manus.buildList.clearSelection()
+    with monkeypatch.context() as mp:
+        mp.setattr("novelwriter.tools.manusbuild.GuiManuscriptBuild.exec_", lambda *a: None)
+
+        # With no selection, no dialog should be created
+        manus.btnBuild.click()
+        for obj in manus.children():
+            assert not isinstance(obj, GuiManuscriptBuild)
+
+        # With a selection, there should be one
+        manus.buildList.setCurrentRow(0)
+        manus.btnBuild.click()
+        for obj in manus.children():
+            if isinstance(obj, GuiManuscriptBuild):
+                obj.close()
+                break
+        else:
+            assert False
+
+    # Print Preview
+    # =============
+
+    with monkeypatch.context() as mp:
+        mp.setattr(QPrintPreviewDialog, "exec_", lambda *a: None)
+        manus.btnPrint.click()
+        for obj in manus.children():
+            if isinstance(obj, QPrintPreviewDialog):
+                obj.show()
+                obj.close()
+                break
+        else:
+            assert False
+
+    # Finish
+    manus.close()
+    # qtbot.stop()
+
+# END Test testManuscript_Features
diff --git a/tests/tools.py b/tests/tools.py
index 12b6624c9..e07912ae0 100644
--- a/tests/tools.py
+++ b/tests/tools.py
@@ -112,32 +112,28 @@ def cmpFiles(
     return not diffFound
 
 
-def getGuiItem(theName):
-    """Returns a QtWidget based on its objectName.
-    """
+def getGuiItem(name: str):
+    """Returns a QtWidget based on its objectName."""
     for qWidget in qApp.topLevelWidgets():
-        if qWidget.objectName() == theName:
+        if qWidget.objectName() == name:
             return qWidget
     return None
 
 
-def readFile(fileName):
-    """Returns the content of a file as a string.
-    """
+def readFile(fileName: str | Path):
+    """Returns the content of a file as a string."""
     with open(fileName, mode="r", encoding="utf-8") as inFile:
         return inFile.read()
 
 
-def writeFile(fileName, fileData):
-    """Write the contents of a string to a file.
-    """
+def writeFile(fileName: str | Path, fileData: str):
+    """Write the contents of a string to a file."""
     with open(fileName, mode="w", encoding="utf-8") as outFile:
         outFile.write(fileData)
 
 
-def cleanProject(path):
-    """Delete all generated files in a project.
-    """
+def cleanProject(path: str | Path):
+    """Delete all generated files in a project."""
     path = Path(path)
     cacheDir = path / "cache"
     if cacheDir.is_dir():