diff --git a/inc/change.class.php b/inc/change.class.php
index 0aa10a6..f66e41a 100644
--- a/inc/change.class.php
+++ b/inc/change.class.php
@@ -199,7 +199,7 @@ public static function pdfMain(PluginPdfSimplePDF $pdf, Change $job)
         // Observer
         $users     = [];
         $listusers = '';
-        $watcher   = '<b><i>' . sprintf(__s('%1$s: %2$s') . '</i></b>', __s('Watcher'), $listusers);
+        $watcher   = '<b><i>' . sprintf(__s('%1$s: %2$s') . '</i></b>', _n('Observer', 'Observers', 1), $listusers);
         foreach ($job->getUsers(CommonITILActor::OBSERVER) as $d) {
             if ($d['users_id']) {
                 $tmp = Toolbox::stripTags($dbu->getUserName($d['users_id']));
@@ -220,7 +220,7 @@ public static function pdfMain(PluginPdfSimplePDF $pdf, Change $job)
         $listgroups   = '';
         $watchergroup = '<b><i>' . sprintf(
             __s('%1$s: %2$s') . '</i></b>',
-            __s('Watcher group'),
+            _n('Observer group', 'Observer groups', 1),
             $listgroups,
         );
         foreach ($job->getGroups(CommonITILActor::OBSERVER) as $d) {
diff --git a/inc/group.class.php b/inc/group.class.php
index 5b7e82c..31eea5d 100644
--- a/inc/group.class.php
+++ b/inc/group.class.php
@@ -71,7 +71,7 @@ public static function pdfMain(PluginPdfSimplePDF $pdf, Group $item)
             ),
             '<b><i>' . sprintf(
                 __s('%1$s - %2$s'),
-                __s('Watcher') . '</i></b>',
+                _n('Observer', 'Observers', 1) . '</i></b>',
                 Dropdown::getYesNo($item->fields['is_watcher']),
             ),
             '<b><i>' . sprintf(
diff --git a/inc/problem.class.php b/inc/problem.class.php
index 0bcd65a..f2ce73b 100644
--- a/inc/problem.class.php
+++ b/inc/problem.class.php
@@ -196,7 +196,7 @@ public static function pdfMain(PluginPdfSimplePDF $pdf, Problem $job)
         // Observer
         $users     = [];
         $listusers = '';
-        $watcher   = '<b><i>' . sprintf(__s('%1$s: %2$s') . '</i></b>', __s('Watcher'), $listusers);
+        $watcher   = '<b><i>' . sprintf(__s('%1$s: %2$s') . '</i></b>', _n('Observer', 'Observers', 1), $listusers);
         foreach ($job->getUsers(CommonITILActor::OBSERVER) as $d) {
             if ($d['users_id']) {
                 $tmp = Toolbox::stripTags($dbu->getUserName($d['users_id']));
@@ -217,7 +217,7 @@ public static function pdfMain(PluginPdfSimplePDF $pdf, Problem $job)
         $listgroups   = '';
         $watchergroup = '<b><i>' . sprintf(
             __s('%1$s: %2$s') . '</i></b>',
-            __s('Watcher group'),
+            _n('Observer group', 'Observer groups', 1),
             $listgroups,
         );
         foreach ($job->getGroups(CommonITILActor::OBSERVER) as $d) {
diff --git a/inc/ticket.class.php b/inc/ticket.class.php
index a09d9ed..49a1213 100644
--- a/inc/ticket.class.php
+++ b/inc/ticket.class.php
@@ -355,7 +355,7 @@ public static function pdfMain(PluginPdfSimplePDF $pdf, Ticket $job)
         // Observer
         $users     = [];
         $listusers = '';
-        $watcher   = '<b><i>' . sprintf(__s('%1$s: %2$s') . '</i></b>', __s('Watcher'), $listusers);
+        $watcher   = '<b><i>' . sprintf(__s('%1$s: %2$s') . '</i></b>', _n('Observer', 'Observers', 1), $listusers);
         foreach ($job->getUsers(CommonITILActor::OBSERVER) as $d) {
             if ($d['users_id']) {
                 $tmp = Toolbox::stripTags($dbu->getUserName($d['users_id']));
@@ -376,7 +376,7 @@ public static function pdfMain(PluginPdfSimplePDF $pdf, Ticket $job)
         $listgroups   = '';
         $watchergroup = '<b><i>' . sprintf(
             __s('%1$s: %2$s') . '</i></b>',
-            __s('Watcher group'),
+            _n('Observer group', 'Observer groups', 1),
             $listgroups,
         );
         foreach ($job->getGroups(CommonITILActor::OBSERVER) as $d) {