Fix #4192
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 60cf4cf..f9f451d 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -22,6 +22,7 @@
 -  Fixed a bug where :doc:`Database Transaction <database/transactions>` methods ``trans_begin()``, ``trans_commit()``, ``trans_rollback()`` ignored failures.
 -  Fixed a bug where all :doc:`Database Transaction <database/transactions>` methods returned TRUE while transactions are actually disabled.
 -  Fixed a bug where :doc:`common function <general/common_functions>` :php:func:`html_escape()` modified keys of its array inputs.
+-  Fixed a bug (#4192) - :doc:`Email Library <libraries/email>` wouldn't always have proper Quoted-printable encoding due to a bug in PHP's own ``mb_mime_encodeheader()`` function.
 
 Version 3.0.2
 =============