Add changelog entry for #501

docs/CHANGELOG.md

diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 044048c..ab37518 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -38,7 +38,7 @@
 * print final line without newline on Bash 3.2 for midtest (ERREXIT) failures
   too (#495, #145)
 * abort with error on missing flock/shlock when running in parallel mode  (#496)
-* improved `set -u` test and fixed some unset variable accesses (#498)
+* improved `set -u` test and fixed some unset variable accesses (#498, #501)
 
 #### Documentation