diff --git a/pyproject.toml b/pyproject.toml
index 9dcd7bb..d3719e7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,9 +33,18 @@ dependencies = [
 include = ["moderngl_window", "moderngl_window.*"]
 
 [project.optional-dependencies]
-dev = ["pytest", "mypy", "coverage", "pywavefront", "trimesh", "scipy", "build"]
+dev = [
+    "pytest",
+    "mypy",
+    "coverage",
+    "pywavefront",
+    "trimesh",
+    "scipy",
+    "build",
+    "flake8",
+]
 docs = ["Sphinx~=7.2.6 ", "sphinx-rtd-theme~=1.3.0 ", "doc8"]
-imgui = ["imgui-bundle"]                                                         # 1.6.0 originally
+imgui = ["imgui-bundle"] # 1.6.0 originally
 pygame = ["pygame>=2.0.1"]
 pygame-ce = ["pygame-ce>=2.0.1"]
 tk = ["pyopengltk>=0.0.3"]