diff --git a/.github/workflows/test_linux_3.8.yml b/.github/workflows/test_linux_3.8.yml
index 502de464..dd27ce70 100644
--- a/.github/workflows/test_linux_3.8.yml
+++ b/.github/workflows/test_linux_3.8.yml
@@ -32,6 +32,6 @@ jobs:
       - name: Run Tests
         run: |
           export QT_QPA_PLATFORM=offscreen
-          pytest -v --timeout=60
+          pytest -v --cov-nw --timeout=60
       - name: Upload to Codecov
         uses: codecov/codecov-action@v1
diff --git a/.github/workflows/test_mac.yml b/.github/workflows/test_mac.yml
index 0478bf71..d409f81e 100644
--- a/.github/workflows/test_mac.yml
+++ b/.github/workflows/test_mac.yml
@@ -31,6 +31,6 @@ jobs:
       - name: Run Tests
         run: |
           export QT_QPA_PLATFORM=offscreen
-          pytest -v --timeout=60
+          pytest -v --cov-nw --timeout=60
       - name: Upload to Codecov
         uses: codecov/codecov-action@v1
diff --git a/.github/workflows/test_win.yml b/.github/workflows/test_win.yml
index aa9ef284..ebdee693 100644
--- a/.github/workflows/test_win.yml
+++ b/.github/workflows/test_win.yml
@@ -27,6 +27,6 @@ jobs:
           pip install codecov
       - name: Run Tests
         run: |
-          pytest -v --timeout=60
+          pytest -v --cov-nw --timeout=60
       - name: Upload to Codecov
         uses: codecov/codecov-action@v1
diff --git a/nw/__init__.py b/nw/__init__.py
index 199d20ca..aa755a2e 100644
--- a/nw/__init__.py
+++ b/nw/__init__.py
@@ -28,7 +28,6 @@
 import sys
 import getopt
 import logging
-import os
 
 from PyQt5.QtGui import QIcon
 from PyQt5.QtWidgets import QApplication, QErrorMessage
@@ -158,12 +157,12 @@ def main(sysArgs=None):
     for inOpt, inArg in inOpts:
         if inOpt in ("-h", "--help"):
             print(helpMsg)
-            sys.exit()
+            sys.exit(0)
         elif inOpt in ("-v", "--version"):
             print("novelWriter %s Version %s [%s]" % (
                 __status__, __version__, __date__)
             )
-            sys.exit()
+            sys.exit(0)
         elif inOpt == "--info":
             debugLevel = logging.INFO
         elif inOpt == "--debug":
@@ -224,19 +223,20 @@ def main(sysArgs=None):
         errorData.append("Python module 'lxml' is missing.")
 
     if errorData:
-        errApp = QApplication([])
-        errMsg = QErrorMessage()
-        errMsg.resize(500, 300)
-        errMsg.showMessage((
-            "<h3>A critical error has been encountered</h3>"
-            "<p>novelWriter cannot start due to the following issues:<p>"
-            "<p>&nbsp;-&nbsp;%s</p>"
-            "<p>Shutting down ...</p>"
-        ) % (
-            "<br>&nbsp;-&nbsp;".join(errorData)
-        ))
-        errApp.exec_()
-        sys.exit(1)
+        if not testMode:
+            errApp = QApplication([])
+            errMsg = QErrorMessage()
+            errMsg.resize(500, 300)
+            errMsg.showMessage((
+                "<h3>A critical error has been encountered</h3>"
+                "<p>novelWriter cannot start due to the following issues:<p>"
+                "<p>&nbsp;-&nbsp;%s</p>"
+                "<p>Shutting down ...</p>"
+            ) % (
+                "<br>&nbsp;-&nbsp;".join(errorData)
+            ))
+            errApp.exec_()
+        sys.exit(10 + len(errorData))
 
     # Finish initialising config
     CONFIG.initConfig(confPath, dataPath)
diff --git a/tests/test_gui.py b/tests/test_gui.py
index 0334cf2d..3bffd372 100644
--- a/tests/test_gui.py
+++ b/tests/test_gui.py
@@ -6,6 +6,7 @@ import nw
 import pytest
 import logging
 import os
+import sys
 
 from shutil import copyfile
 from nwtools import cmpFiles
@@ -25,16 +26,17 @@ typeDelay = 1
 stepDelay = 20
 
 @pytest.mark.gui
-def testLaunch(qtbot, nwFuncTemp, nwTemp):
+def testLaunch(qtbot, monkeypatch, nwFuncTemp, nwTemp):
 
-    # Log Levels
+    # Defaults
     nwGUI = nw.main(
-        ["--testmode", "--config=%s" % nwFuncTemp, "--data=%s" % nwTemp]
+        ["--testmode", "--config=%s" % nwFuncTemp, "--data=%s" % nwTemp, "--style=Fusion"]
     )
     assert nw.logger.getEffectiveLevel() == logging.WARNING
     nwGUI.closeMain()
     nwGUI.close()
 
+    # Log Levels
     nwGUI = nw.main(
         ["--testmode", "--info", "--config=%s" % nwFuncTemp, "--data=%s" % nwTemp]
     )
@@ -56,20 +58,46 @@ def testLaunch(qtbot, nwFuncTemp, nwTemp):
     nwGUI.closeMain()
     nwGUI.close()
 
-    # Other options
-    with pytest.raises(SystemExit):
+    # Help and Version
+    with pytest.raises(SystemExit) as ex:
         nwGUI = nw.main(
             ["--testmode", "--help", "--config=%s" % nwFuncTemp, "--data=%s" % nwTemp]
         )
     nwGUI.closeMain()
     nwGUI.close()
+    assert ex.value.code == 0
 
-    with pytest.raises(SystemExit):
+    with pytest.raises(SystemExit) as ex:
+        nwGUI = nw.main(
+            ["--testmode", "--version", "--config=%s" % nwFuncTemp, "--data=%s" % nwTemp]
+        )
+    nwGUI.closeMain()
+    nwGUI.close()
+    assert ex.value.code == 0
+
+    # Invalid options
+    with pytest.raises(SystemExit) as ex:
         nwGUI = nw.main(
             ["--testmode", "--invalid", "--config=%s" % nwFuncTemp, "--data=%s" % nwTemp]
         )
     nwGUI.closeMain()
     nwGUI.close()
+    assert ex.value.code == 2
+
+    # Simulate import error
+    monkeypatch.setitem(sys.modules, "PyQt5.QtSvg", None)
+    monkeypatch.setitem(sys.modules, "lxml", None)
+    monkeypatch.setattr("sys.hexversion", 0x0)
+    monkeypatch.setattr("nw.CONFIG.verQtValue", 50000)
+    monkeypatch.setattr("nw.CONFIG.verPyQtValue", 50000)
+    with pytest.raises(SystemExit) as ex:
+        nwGUI = nw.main(
+            ["--testmode", "--config=%s" % nwFuncTemp, "--data=%s" % nwTemp]
+        )
+    nwGUI.closeMain()
+    nwGUI.close()
+    assert ex.value.code == 15
+    monkeypatch.undo()
 
 @pytest.mark.gui
 def testDocEditor(qtbot, yesToAll, nwFuncTemp, nwTempGUI, nwRef, nwTemp):