diff --git a/pyproject.toml b/pyproject.toml
index e24dc8a176..f8a87b9ec4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -54,6 +54,7 @@ dev = [
     "pydata-sphinx-theme>=0.12",
     "pyepics>=3.4.2",
     "pyside6",
+    "pyside6-stubs",
     "pytest",
     "pytest-asyncio",
     "pytest-cov",