diff --git a/zipline/pipeline/engine.py b/zipline/pipeline/engine.py
index 1fea22f0..3f290b1f 100644
--- a/zipline/pipeline/engine.py
+++ b/zipline/pipeline/engine.py
@@ -35,7 +35,7 @@ class PipelineEngine(with_metaclass(ABCMeta)):
         """
         Compute values for `pipeline` between `start_date` and `end_date`.
 
-        Returns a DataFrame with a MultiIndex of (date, asset) pairs
+        Returns a DataFrame with a MultiIndex of (date, asset) pairs.
 
         Parameters
         ----------