diff --git a/addressbook/inc/class.addressbook_vcal.inc.php b/addressbook/inc/class.addressbook_vcal.inc.php
index 5f1f7d7e78..24dac95dba 100644
--- a/addressbook/inc/class.addressbook_vcal.inc.php
+++ b/addressbook/inc/class.addressbook_vcal.inc.php
@@ -388,7 +388,7 @@ class addressbook_vcal extends addressbook_bo
 								{
 										$options['ENCODING'] = 'FUNAMBOL-QP';
 								}
-								elseif (preg_match('/([\000-\012\015\016\020-\037\075])/', $value))
+								elseif (preg_match(Api\CalDAV\Handler::REQUIRE_QUOTED_PRINTABLE_ENCODING, $value))
 								{
 									$options['ENCODING'] = 'QUOTED-PRINTABLE';
 								}
@@ -467,7 +467,7 @@ class addressbook_vcal extends addressbook_bo
 								{
 									$options['ENCODING'] = 'FUNAMBOL-QP';
 								}
-								elseif (preg_match('/([\000-\012\015\016\020-\037\075])/', $value))
+								elseif (preg_match(Api\CalDAV\Handler::REQUIRE_QUOTED_PRINTABLE_ENCODING, $value))
 								{
 									$options['ENCODING'] = 'QUOTED-PRINTABLE';
 								}
diff --git a/api/src/CalDAV/Handler.php b/api/src/CalDAV/Handler.php
index 1999c82243..c7d5983083 100644
--- a/api/src/CalDAV/Handler.php
+++ b/api/src/CalDAV/Handler.php
@@ -114,6 +114,13 @@ abstract class Handler
 	 */
 	var $new_id;
 
+	/**
+	 * Regular expression to identify content requiring QUOTED-PRINTABLE encoding
+	 *
+	 * Used in {addressbook,calendar,infolog}/inc/class.*cal.inc.php
+	 */
+	const REQUIRE_QUOTED_PRINTABLE_ENCODING = '/([\000-\012\013\015\016\020-\037\075])/';
+
 	/**
 	 * Constructor
 	 *
diff --git a/calendar/inc/class.calendar_ical.inc.php b/calendar/inc/class.calendar_ical.inc.php
index d0dce20c22..65bf664fb7 100644
--- a/calendar/inc/class.calendar_ical.inc.php
+++ b/calendar/inc/class.calendar_ical.inc.php
@@ -1034,7 +1034,7 @@ class calendar_ical extends calendar_boupdate
 								else
 								{
 									$paramData['CHARSET'] = '';
-									if (preg_match('/([\000-\012\015\016\020-\037\075])/', $valueData))
+									if (preg_match(Api\CalDAV\Handler::REQUIRE_QUOTED_PRINTABLE_ENCODING, $valueData))
 									{
 										$paramData['ENCODING'] = 'QUOTED-PRINTABLE';
 									}
diff --git a/infolog/inc/class.infolog_ical.inc.php b/infolog/inc/class.infolog_ical.inc.php
index be83e4cb4f..79c5ee6f8c 100644
--- a/infolog/inc/class.infolog_ical.inc.php
+++ b/infolog/inc/class.infolog_ical.inc.php
@@ -299,7 +299,7 @@ class infolog_ical extends infolog_bo
 						{
 							$options['CHARSET'] = '';
 
-							if (preg_match('/([\000-\012\015\016\020-\037\075])/', $value))
+							if (preg_match(Api\CalDAV\Handler::REQUIRE_QUOTED_PRINTABLE_ENCODING, $value))
 							{
 								$options['ENCODING'] = 'QUOTED-PRINTABLE';
 							}
@@ -972,7 +972,7 @@ class infolog_ical extends infolog_bo
 								{
 									$options['CHARSET'] = '';
 
-									if (preg_match('/([\000-\012\015\016\020-\037\075])/', $value))
+									if (preg_match(Api\CalDAV\Handler::REQUIRE_QUOTED_PRINTABLE_ENCODING, $value))
 									{
 										$options['ENCODING'] = 'QUOTED-PRINTABLE';
 									}