diff --git a/noxfile.py b/noxfile.py
index d0d1554a8..1a98cf853 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -67,7 +67,6 @@ def mypy(session: Session) -> None:
     args = session.posargs or ["singer_sdk"]
     session.install(".")
     session.install(
-        "backports-datetime-fromisoformat",
         "mypy",
         "pytest",
         "importlib-resources",
diff --git a/pyproject.toml b/pyproject.toml
index 3a5bd96b8..fba28f97e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -201,6 +201,7 @@ warn_return_any = true
 [[tool.mypy.overrides]]
 ignore_missing_imports = true
 module = [
+    "backports.datetime_fromisoformat.*",
     "bcrypt.*",
     "joblib.*",
     "pyarrow.*",