diff --git a/core/modules/system/system.modules.js b/core/modules/system/system.modules.js
index 4964a1a..3a13ad9 100644
--- a/core/modules/system/system.modules.js
+++ b/core/modules/system/system.modules.js
@@ -50,6 +50,10 @@
           // Hide the package <details> if they don't have any visible rows.
           // Note that we first show() all <details> to be able to use ':visible'.
           $details.attr('open', true).each(hidePackageDetails);
+
+          Drupal.announce(
+            Drupal.t('The list of modules has been altered by a search.')
+          );
         }
         else if (searching) {
           searching = false;
@@ -62,12 +66,22 @@
         }
       }
 
+      function preventEnterKey(event) {
+        if (event.which === 13) {
+          event.preventDefault();
+          event.stopPropagation();
+        }
+      }
+
       if ($table.length) {
         $rowsAndDetails = $table.find('tr, details');
         $rows = $table.find('tbody tr');
         $details = $rowsAndDetails.filter('.package-listing');
 
-        $input.on('keyup', filterModuleList);
+        $input.on({
+          keyup: filterModuleList,
+          keydown: preventEnterKey
+        });
       }
     }
   };