diff --git a/pyproject.toml b/pyproject.toml
index ab85ed2c2..fb427faa1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -226,6 +226,7 @@ ignore = [
 # These are tentative
 include = ["**/*.py"]
 pythonVersion = "3.8.6"
+# FIXME understand the difference
 #typeCheckingMode = "strict"
 #useLibraryCodeForTypes = true
 reportGeneralTypeIssues = true