diff --git a/src/backend/optimizer/README b/src/backend/optimizer/README
index 15af9ceff5..53f02b5300 100644
--- a/src/backend/optimizer/README
+++ b/src/backend/optimizer/README
@@ -1106,7 +1106,7 @@ PartitionSchemeData object.  This reduces memory consumed by
 PartitionSchemeData objects and makes it easy to compare the partition schemes
 of joining relations.
 
-Partition-wise aggregates/grouping
+Partitionwise aggregates/grouping
 ----------------------------------
 
 If the GROUP BY clause has contains all of the partition keys, all the rows