diff --git a/README.md b/README.md
index bef00ce..e7ed2a0 100644
--- a/README.md
+++ b/README.md
@@ -684,7 +684,7 @@ The following guidelines indicate when the use of an index should be reconsidere
 
 **- Tables that have frequent, large batch updates or insert operations.**
 
-**- Indexes should not be used on columns that contain a high number of NULL values.
+**- Indexes should not be used on columns that contain a high number of NULL values.**
 
 **- Columns that are frequently manipulated should not be indexed.