diff --git a/test/completion/import_tree/invisible_pkg.py b/test/completion/import_tree/invisible_pkg.py
new file mode 100644
index 00000000..9c78ce2f
--- /dev/null
+++ b/test/completion/import_tree/invisible_pkg.py
@@ -0,0 +1,7 @@
+"""
+It should not be possible to import this pkg except for the import_tree itself,
+because it is overwritten there. (It would be possible with a sys.path
+modification, though).
+"""
+
+foo = 1.0