diff --git a/pyproject.toml b/pyproject.toml
index 26b8d0f5f4..e007a4435c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -52,7 +52,7 @@ dev = [
     "pre-commit",
     "pydata-sphinx-theme>=0.12",
     "pyepics>=3.4.2",
-    "pyside6=6.6.2",
+    "pyside6==6.6.2",
     "pytest",
     "pytest-asyncio",
     "pytest-cov",