diff --git a/validphys2/src/validphys/__init__.py b/validphys2/src/validphys/__init__.py
index 8dee4bf825..2848b606d1 100644
--- a/validphys2/src/validphys/__init__.py
+++ b/validphys2/src/validphys/__init__.py
@@ -1 +1,4 @@
-from ._version import __version__
+try:
+    from ._version import __version__
+except ModuleNotFoundError:
+    raise ModuleNotFoundError("`_version` not found, you might need to reinstall nnpdf (e.g., `pip install .`) if you installed last before nnpdf 4.0.8")