diff --git a/doc/feature_request/historical_performance_data.rst b/doc/feature_request/historical_performance_data.rst
index 6f1997ef..4ccb8ca3 100644
--- a/doc/feature_request/historical_performance_data.rst
+++ b/doc/feature_request/historical_performance_data.rst
@@ -6,7 +6,7 @@ Historical performance data
 Use case
 --------
 
-OpenStack is really rapidly developed. Hundreds patches are merged daily
+OpenStack is really rapidly developed. Hundreds of patches are merged daily
 and it's really hard to track how performance is changed during time.
 It will be nice to have a way to track performance of major functionality
 of OpenStack running periodically rally task and building graphs that represent