diff --git a/tests/cpydiff/core_import_all.py b/tests/cpydiff/core_import_all.py
new file mode 100644
index 0000000000..5adf9ae3eb
--- /dev/null
+++ b/tests/cpydiff/core_import_all.py
@@ -0,0 +1,9 @@
+"""
+categories: Core,import
+description: __all__ is unsupported in __init__.py in MicroPython.
+cause: Not implemented.
+workaround: Manually import the sub-modules directly in __init__.py using ``from . import foo, bar``.
+"""
+from modules3 import *
+
+foo.hello()
diff --git a/tests/cpydiff/modules3/__init__.py b/tests/cpydiff/modules3/__init__.py
new file mode 100644
index 0000000000..27a2bf2ad9
--- /dev/null
+++ b/tests/cpydiff/modules3/__init__.py
@@ -0,0 +1 @@
+__all__ = ["foo"]
diff --git a/tests/cpydiff/modules3/foo.py b/tests/cpydiff/modules3/foo.py
new file mode 100644
index 0000000000..dd9b9d4ddd
--- /dev/null
+++ b/tests/cpydiff/modules3/foo.py
@@ -0,0 +1,2 @@
+def hello():
+    print("hello")