diff --git a/pydu/itercompat.py b/pydu/itercompat.py
index 9895e3f..4d6537f 100644
--- a/pydu/itercompat.py
+++ b/pydu/itercompat.py
@@ -1,5 +1,5 @@
 def is_iterable(x):
-    "An implementation independent way of checking for iterables"
+    """An implementation independent way of checking for iterables."""
     try:
         iter(x)
     except TypeError: