diff -r ab000b7b9ac5 pypy/module/cpyext/test/test_arraymodule.py
--- a/pypy/module/cpyext/test/test_arraymodule.py	Sun Apr 08 00:46:15 2018 +0300
+++ b/pypy/module/cpyext/test/test_arraymodule.py	Sun Apr 08 10:21:14 2018 +0300
@@ -198,3 +198,9 @@
             assert Sub.__module__ == 'pypy.module.cpyext.test.test_arraymodule'
             assert str(Sub) == "<class 'pypy.module.cpyext.test.test_arraymodule.Sub'>"
         
+    def test_getset(self):
+        # issue #2788
+        module = self.import_module(name='array')
+        arr = module.array('i', [1,2,3])
+        assert arr.typecode == 'i'
+        raises(AttributeError, setattr, arr, 'typecode', 'f')