diff --git a/README.md b/README.md
index d5a94924..f588ab49 100644
--- a/README.md
+++ b/README.md
@@ -479,7 +479,7 @@ strings that they parse.
 
 ### Ranges
 
-* `validRange(range)`: Return the valid range or null if it's not valid
+* `validRange(range)`: Return the valid range or null if it's not valid.
 * `satisfies(version, range)`: Return true if the version satisfies the
   range.
 * `maxSatisfying(versions, range)`: Return the highest version in the list