diff --git a/CHANGELOG.md b/CHANGELOG.md
index b4f1a3e9..b1378a30 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,3 +8,4 @@
 - Implement `Sub<impl Into<u64>>` for `ByteSize`.
 - Implement `SubAssign<ByteSize>` for `ByteSize`.
 - Implement `SubAssign<impl Into<u64>>` for `ByteSize`.
+- Reject parsing non-unit characters after whitespace.