diff -u b/core/modules/system/js/system.modules.js b/core/modules/system/js/system.modules.js
--- b/core/modules/system/js/system.modules.js
+++ b/core/modules/system/js/system.modules.js
@@ -43,8 +43,15 @@
 
           $details.attr('open', true).each(hidePackageDetails);
 
-          Drupal.announce(Drupal.t('!modules modules are available in the modified list.', { '!modules': $rowsAndDetails.find('tbody tr:visible').length }));
-        } else if (searching) {
+          Drupal.announce(
+            Drupal.formatPlural(
+              $rowsAndDetails.find('tbody tr:visible').length,
+              '1 module is available in the modified list.',
+              '@count modules are available in the modified list.'
+            )
+          );
+        }
+        else if (searching) {
           searching = false;
           $rowsAndDetails.show();
 
@@ -63,10 +70,9 @@
           $details.attr('open', true).each(hidePackageDetails);
 
           Drupal.announce(
-            Drupal.formatPlural(
-              $rowsAndDetails.find('tbody tr:visible').length,
-              '1 module is available in the modified list.',
-              '@count modules are available in the modified list.'
+            Drupal.t(
+              '!modules modules are available in the modified list.',
+              {'!modules': $rowsAndDetails.find('tbody tr:visible').length}
             )
           );
         }