diff --git a/htdocs/core/actions_extrafields.inc.php b/htdocs/core/actions_extrafields.inc.php
index 48e52316faf..7a7ab380e29 100644
--- a/htdocs/core/actions_extrafields.inc.php
+++ b/htdocs/core/actions_extrafields.inc.php
@@ -147,7 +147,7 @@ if ($action == 'add') {
 
 		if (!$error) {
 			// attrname must be alphabetical and lower case only
-			if (GETPOSTISSET("attrname") && preg_match("/^[a-z0-9-_]+$/", GETPOST('attrname', 'aZ09')) && !is_numeric(GETPOST('attrname', 'aZ09'))) {
+			if (GETPOSTISSET("attrname") && preg_match("/^[a-z0-9_]+$/", GETPOST('attrname', 'aZ09')) && !is_numeric(GETPOST('attrname', 'aZ09'))) {
 				// Construct array for parameter (value of select list)
 				$default_value = GETPOST('default_value', 'alpha');
 				$parameters = $param;
diff --git a/htdocs/core/tpl/admin_extrafields_add.tpl.php b/htdocs/core/tpl/admin_extrafields_add.tpl.php
index 438e3d3f93e..1dbc0861adb 100644
--- a/htdocs/core/tpl/admin_extrafields_add.tpl.php
+++ b/htdocs/core/tpl/admin_extrafields_add.tpl.php
@@ -147,7 +147,7 @@ $listofexamplesforlink = 'Societe:societe/class/societe.class.php<br>Contact:con
 <!-- Label -->
 <tr><td class="titlefieldcreate fieldrequired"><?php echo $langs->trans("LabelOrTranslationKey"); ?></td><td class="valeur"><input type="text" name="label" class="width200" value="<?php echo GETPOST('label', 'alpha'); ?>" autofocus></td></tr>
 <!-- Code -->
-<tr><td class="fieldrequired"><?php echo $langs->trans("AttributeCode"); ?></td><td class="valeur"><input type="text" name="attrname" id="attrname"  size="10" value="<?php echo GETPOST('attrname', 'alpha'); ?>"> <span class="opacitymedium">(<?php echo $langs->trans("AlphaNumOnlyLowerCharsAndNoSpace"); ?>)</span></td></tr>
+<tr><td class="fieldrequired"><?php echo $langs->trans("AttributeCode"); ?></td><td class="valeur"><input type="text" name="attrname" id="attrname"  size="10" value="<?php echo GETPOST('attrname', 'alpha'); ?>" pattern="\w+"> <span class="opacitymedium">(<?php echo $langs->trans("AlphaNumOnlyLowerCharsAndNoSpace"); ?>)</span></td></tr>
 <!-- Type -->
 <tr><td class="fieldrequired"><?php echo $langs->trans("Type"); ?></td><td class="valeur">
 <?php print $form->selectarray('type', $type2label, GETPOST('type', 'alpha'), 0, 0, 0, '', 0, 0, 0, '', '', 1); ?>