diff --git a/libbmc/isbn.py b/libbmc/isbn.py
index a6f3faa..5c5904a 100644
--- a/libbmc/isbn.py
+++ b/libbmc/isbn.py
@@ -37,7 +37,11 @@ def is_valid(isbn):
     >>> is_valid("123456789X")
     True
     """
-    return not isbnlib.notisbn(isbn)
+    return (
+        (not isbnlib.notisbn(isbn)) and (
+            isbnlib.get_canonical_isbn(isbn) == isbn or
+            isbnlib.mask(isbnlib.get_canonical_isbn(isbn)) == isbn)
+    )
 
 
 def extract_from_text(text):
diff --git a/libbmc/tools.py b/libbmc/tools.py
index 3e6e9ed..b278700 100644
--- a/libbmc/tools.py
+++ b/libbmc/tools.py
@@ -82,7 +82,8 @@ def batch(iterable, size):
     :params size: Size of the batches.
     :returns: A new batch of the given size at each time.
 
-    # TODO: Unittest
+    >>> [list(i) for i in batch([1, 2, 3, 4, 5], 2)]
+    [[1, 2], [3, 4], [5]]
     """
     it = iter(iterable)
     while True: