diff --git a/pyproject_toml_builder.py b/pyproject_toml_builder.py
index be1ecc2..3c524ce 100644
--- a/pyproject_toml_builder.py
+++ b/pyproject_toml_builder.py
@@ -247,7 +247,7 @@ def get_init_version(ppath: Path) -> tuple[Path, str | None]:
                         else:
                             raise Exception(
                                 f"'__version__' must be in the semantic version format: "
-                                f"{Path(f.name).relative_to(self.root)}/ -> '{line.strip()}'"
+                                f"{ppath.name}/__init__.py -> '{line.strip()}'"
                             )
                 return Path(f.name), None