diff --git a/system/libraries/Email.php b/system/libraries/Email.php
index c39a26a..88398d3 100644
--- a/system/libraries/Email.php
+++ b/system/libraries/Email.php
@@ -1079,6 +1079,11 @@
 	 */
 	public function valid_email($email)
 	{
+		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
+		{
+			$email = substr($email, 0, ++$atpos).idn_to_ascii(substr($email, $atpos));
+		}
+
 		return (bool) filter_var($email, FILTER_VALIDATE_EMAIL);
 	}
 
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index dc5d17f..555a659 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -1225,6 +1225,11 @@
 	 */
 	public function valid_email($str)
 	{
+		if (function_exists('idn_to_ascii') && $atpos = strpos($email, '@'))
+		{
+			$email = substr($email, 0, ++$atpos).idn_to_ascii(substr($email, $atpos));
+		}
+
 		return (bool) filter_var($str, FILTER_VALIDATE_EMAIL);
 	}
 
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 8492be2..40c24a6 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -347,6 +347,7 @@
       -  Added rule **alpha_numeric_spaces**.
       -  Added support for custom error messages per field rule.
       -  Added support for callable rules when they are passed as an array.
+      -  Added support for non-ASCII domains in **valid_email** rule, depending on the Intl extension.
 
    -  :doc:`Caching Library <libraries/caching>` changes include:
 
@@ -375,6 +376,7 @@
       -  Added an optional parameter to ``print_debugger()`` to allow specifying which parts of the message should be printed ('headers', 'subject', 'body').
       -  Added SMTP keepalive option to avoid opening the connection for each ``send()`` call. Accessible as ``$smtp_keepalive``.
       -  Public method ``set_header()`` now filters the input by removing all "\\r" and "\\n" characters.
+      -  Added support for non-ASCII domains in ``valid_email()``, depending on the Intl extension.
 
    -  :doc:`Pagination Library <libraries/pagination>` changes include: