diff --git a/src/poetry/layouts/layout.py b/src/poetry/layouts/layout.py
index f5dfd28e950..e81d201ebb8 100644
--- a/src/poetry/layouts/layout.py
+++ b/src/poetry/layouts/layout.py
@@ -90,7 +90,11 @@ def package_path(self) -> Path:
     def get_package_include(self) -> InlineTable | None:
         package = inline_table()
 
-        include = self._package_path_relative.parts[0]
+        parts = self._package_path_relative.parts
+        if not parts:
+            return None
+
+        include = parts[0]
         package.append("include", include)  # type: ignore[no-untyped-call]
 
         if self.basedir != Path():