diff --git a/CHANGELOG.md b/CHANGELOG.md
index e72c22e1..fe3a908e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ History for Surveyor
 
 - Handle `nil` in `ResponseMethods#date_value=` and `ResponseMethods#time_value`.
   (#450)
+- Handle `nil` datetime values in `ResponseMethods#to_formatted_s`.  (#459)
 
 1.4.0
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