diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0cfb4b4b..57157467 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -62,6 +62,7 @@ jobs:
           sudo apt-get install --yes libgl1
           # Required to stubtest QtMultimedia
           sudo apt-get install --yes libpulse-mainloop-glib0
+          sudo apt-get install --yes libgl1 libgl1-mesa-dev xvfb x11-utils libdbus-1-3 libxkbcommon-x11-0 libxcb-icccm4 libxcb-image0 libxcb-keysyms1 libxcb-randr0 libxcb-render-util0 libxcb-xinerama0 libxcb-xfixes0
       - name: Install
         run: |
           pip install --upgrade pip setuptools wheel
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 394ea18f..f3d0302e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
    detected by latest mypy 0.930
 * [#183](https://github.com/python-qt-tools/PyQt5-stubs/pull/183) Add missing operations on QSize
 * [#189](https://github.com/python-qt-tools/PyQt5-stubs/pull/189) Fix QListWidget, QTreeWidget and QTableWidget so that their respective items are now optional in many places when used as argument or return value
+* [#165](https://github.com/python-qt-tools/PyQt5-stubs/pull/165) allow `None` as argument for `QLineEdit.setText()`
+
 ## 5.15.2.0
 
 ### Added
diff --git a/PyQt5-stubs/QtWidgets.pyi b/PyQt5-stubs/QtWidgets.pyi
index bff16524..09275fec 100644
--- a/PyQt5-stubs/QtWidgets.pyi
+++ b/PyQt5-stubs/QtWidgets.pyi
@@ -7147,7 +7147,7 @@ class QLineEdit(QWidget):
     def undo(self) -> None: ...
     def selectAll(self) -> None: ...
     def clear(self) -> None: ...
-    def setText(self, a0: str) -> None: ...
+    def setText(self, a0: typing.Optional[str]) -> None: ...
     def hasAcceptableInput(self) -> bool: ...
     def setInputMask(self, inputMask: str) -> None: ...
     def inputMask(self) -> str: ...
diff --git a/setup.py b/setup.py
index 83938fe4..202093d9 100644
--- a/setup.py
+++ b/setup.py
@@ -52,7 +52,7 @@ def find_version(*file_paths):
     packages=["PyQt5-stubs"],
     extras_require={
         "build": ["docker==4.2.0"],
-        "dev": ["mypy", "pytest"],
+        "dev": ["mypy", "pytest", "pytest-xvfb"],
     },
     classifiers=[
         "Development Status :: 4 - Beta",
diff --git a/tests/qlineedit.py b/tests/qlineedit.py
new file mode 100644
index 00000000..542ed44f
--- /dev/null
+++ b/tests/qlineedit.py
@@ -0,0 +1,6 @@
+"""Tests for QLineEdit."""
+from PyQt5.QtWidgets import QLineEdit
+
+# test that QLineEdit.setText() accepts None as parameter
+edit = QLineEdit()
+edit.setText(None)
diff --git a/tests/test_stubs.py b/tests/test_stubs.py
index 2ed54b44..a8be39f9 100644
--- a/tests/test_stubs.py
+++ b/tests/test_stubs.py
@@ -2,11 +2,21 @@
 from pathlib import Path
 import pytest
 from mypy import api
+from PyQt5.QtWidgets import QApplication
 
 
 TESTS_DIR = Path(__file__).parent
 
 
+@pytest.fixture(name="qapplication", scope="session")
+def qapplication_fixture():
+    application = QApplication.instance()
+    if application is None:
+        application = QApplication([])
+
+    return application
+
+
 def gen_tests():
     """List of all tests files included in the directory tests"""
     for path in TESTS_DIR.glob('*.py'):
@@ -53,7 +63,7 @@ def test_stubs_qflags() -> None:
                          list(gen_tests()),
                          ids=[v.name for v in gen_tests()]
                          )
-def test_files(filepath):
+def test_files(filepath, qapplication):
     """Run the test files to make sure they work properly."""
     code = filepath.read_text(encoding='utf-8')
     exec(compile(code, filepath, 'exec'), {})
diff --git a/tox.ini b/tox.ini
index 726866b3..eebb4306 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,6 +8,7 @@ setenv:
   linux: OS_MARKER = linux
   macos: OS_MARKER = macos
   windows: OS_MARKER = windows
+  QT_DEBUG_PLUGINS = 1
 extras =
   dev
 commands =