--- a/contrib/import-checker.py	Thu Mar 31 15:37:21 2016 +0800
+++ b/contrib/import-checker.py	Wed Mar 30 21:54:26 2016 +0200
@@ -184,6 +184,8 @@
     yield 'builtins' # python3 only
     for m in 'fcntl', 'grp', 'pwd', 'termios':  # Unix only
         yield m
+    for m in 'cPickle', 'datetime': # in Python (not C) on PyPy
+        yield m
     stdlib_prefixes = set([sys.prefix, sys.exec_prefix])
     # We need to supplement the list of prefixes for the search to work
     # when run from within a virtualenv.