diff --git a/core/misc/tabledrag.js b/core/misc/tabledrag.js
index d0c6241a232e791771b5ddf02fb20222e0634b0b..1cc75151abffe461e643469e237c0c93fe414219 100644
--- a/core/misc/tabledrag.js
+++ b/core/misc/tabledrag.js
@@ -158,7 +158,7 @@
       if (this.tableSettings.hasOwnProperty(group)) { // Find the first field in this group.
         for (var d in this.tableSettings[group]) {
           if (this.tableSettings[group].hasOwnProperty(d)) {
-            var field = $table.find('.' + this.tableSettings[group][d].target + ':first');
+            var field = $table.find('.' + this.tableSettings[group][d].target).eq(0);
             if (field.length && this.tableSettings[group][d].hidden) {
               hidden = this.tableSettings[group][d].hidden;
               cell = field.closest('td');
@@ -311,18 +311,18 @@
     var self = this;
     var $item = $(item);
     // Add a class to the title link
-    $item.find('td:first a').addClass('menu-item__link');
+    $item.find('td').eq(0).find('a').addClass('menu-item__link');
     // Create the handle.
     var handle = $('<a href="#" class="tabledrag-handle"><div class="handle">&nbsp;</div></a>').attr('title', Drupal.t('Drag to re-order'));
     // Insert the handle after indentations (if any).
-    var $indentationLast = $item.find('td:first .js-indentation:last');
+    var $indentationLast = $item.find('td').eq(0).find('.js-indentation').eq(-1);
     if ($indentationLast.length) {
       $indentationLast.after(handle);
       // Update the total width of indentation in this entire table.
       self.indentCount = Math.max($item.find('.js-indentation').length, self.indentCount);
     }
     else {
-      $item.find('td:first').prepend(handle);
+      $item.find('td').eq(0).prepend(handle);
     }
 
     if (Modernizr.touch) {
@@ -417,7 +417,7 @@
           break;
         case 40: // Down arrow.
         case 63233: // Safari down arrow.
-          var $nextRow = $(self.rowObject.group).filter(':last').next('tr').eq(0);
+          var $nextRow = $(self.rowObject.group).eq(-1).next('tr').eq(0);
           var nextRow = $nextRow.get(0);
           while (nextRow && $nextRow.is(':hidden')) {
             $nextRow = $(nextRow).next('tr').eq(0);
@@ -436,7 +436,7 @@
                 $(nextGroup.group).each(function () {
                   groupHeight += $(this).is(':hidden') ? 0 : this.offsetHeight;
                 });
-                var nextGroupRow = $(nextGroup.group).filter(':last').get(0);
+                var nextGroupRow = $(nextGroup.group).eq(-1).get(0);
                 self.rowObject.swap('after', nextGroupRow);
                 // No need to check for indentation, 0 is the only valid one.
                 window.scrollBy(0, parseInt(groupHeight, 10));
@@ -808,7 +808,7 @@
         // Use the first row in the table as source, because it's guaranteed to
         // be at the root level. Find the first item, then compare this row
         // against it as a sibling.
-        sourceRow = $(this.table).find('tr.draggable:first').get(0);
+        sourceRow = $(this.table).find('tr.draggable').eq(0).get(0);
         if (sourceRow === this.rowObject.element) {
           sourceRow = $(this.rowObject.group[this.rowObject.group.length - 1]).next('tr.draggable').get(0);
         }
@@ -1147,7 +1147,7 @@
     // Determine the valid indentations interval if not available yet.
     if (!this.interval) {
       var prevRow = $(this.element).prev('tr').get(0);
-      var nextRow = $group.filter(':last').next('tr').get(0);
+      var nextRow = $group.eq(-1).next('tr').get(0);
       this.interval = this.validIndentInterval(prevRow, nextRow);
     }
 
@@ -1160,11 +1160,11 @@
     for (var n = 1; n <= Math.abs(indentDiff); n++) {
       // Add or remove indentations.
       if (indentDiff < 0) {
-        $group.find('.js-indentation:first').remove();
+        $group.find('.js-indentation').eq(0).remove();
         this.indents--;
       }
       else {
-        $group.find('td:first').prepend(Drupal.theme('tableDragIndentation'));
+        $group.find('td').eq(0).prepend(Drupal.theme('tableDragIndentation'));
         this.indents++;
       }
     }
@@ -1244,7 +1244,7 @@
    */
   Drupal.tableDrag.prototype.row.prototype.markChanged = function () {
     var marker = Drupal.theme('tableDragChangedMarker');
-    var cell = $(this.element).find('td:first');
+    var cell = $(this.element).find('td').eq(0);
     if (cell.find('abbr.tabledrag-changed').length === 0) {
       cell.append(marker);
     }
diff --git a/core/misc/tableresponsive.js b/core/misc/tableresponsive.js
index 93b7f83704c50ea51fdbcd4307cafba2acf556f7..e13acce40d8bc285fbd50a703f37fe73318e8534 100644
--- a/core/misc/tableresponsive.js
+++ b/core/misc/tableresponsive.js
@@ -89,7 +89,7 @@
           var $header = $(this);
           var position = $header.prevAll('th').length;
           self.$table.find('tbody tr').each(function () {
-            var $cells = $(this).find('td:eq(' + position + ')');
+            var $cells = $(this).find('td').eq(position);
             $cells.show();
             // Keep track of the revealed cells, so they can be hidden later.
             self.$revealedCells = $().add(self.$revealedCells).add($cells);
diff --git a/core/misc/vertical-tabs.js b/core/misc/vertical-tabs.js
index faed095f208c3f62360ebf590ffccde1e6b10d83..1b51850bd828538bb878173c43620e0a7ac4cd41 100644
--- a/core/misc/vertical-tabs.js
+++ b/core/misc/vertical-tabs.js
@@ -55,8 +55,8 @@
           }
         });
 
-        $(tab_list).find('> li:first').addClass('first');
-        $(tab_list).find('> li:last').addClass('last');
+        $(tab_list).find('> li').eq(0).addClass('first');
+        $(tab_list).find('> li').eq(-1).addClass('last');
 
         if (!tab_focus) {
           // If the current URL has a fragment and one of the tabs contains an
@@ -66,7 +66,7 @@
             tab_focus = $locationHash.closest('.vertical-tabs__pane');
           }
           else {
-            tab_focus = $this.find('> .vertical-tabs__pane:first');
+            tab_focus = $this.find('> .vertical-tabs__pane').eq(0);
           }
         }
         if (tab_focus.length) {
@@ -102,7 +102,7 @@
       if (event.keyCode === 13) {
         self.focus();
         // Set focus on the first input field of the visible details/tab pane.
-        $(".vertical-tabs__pane :input:visible:enabled:first").trigger('focus');
+        $(".vertical-tabs__pane :input:visible:enabled").eq(0).trigger('focus');
       }
     });
 
@@ -154,7 +154,7 @@
       // actual DOM element order as jQuery implements sortOrder, but not as public
       // method.
       this.item.parent().children('.vertical-tabs__menu-item').removeClass('first')
-        .filter(':visible:first').addClass('first');
+        .filter(':visible').eq(0).addClass('first');
       // Display the details element.
       this.details.removeClass('vertical-tab--hidden').show();
       // Focus this tab.
@@ -172,11 +172,11 @@
       // actual DOM element order as jQuery implements sortOrder, but not as public
       // method.
       this.item.parent().children('.vertical-tabs__menu-item').removeClass('first')
-        .filter(':visible:first').addClass('first');
+        .filter(':visible').eq(0).addClass('first');
       // Hide the details element.
       this.details.addClass('vertical-tab--hidden').hide();
       // Focus the first visible tab (if there is one).
-      var $firstTab = this.details.siblings('.vertical-tabs__pane:not(.vertical-tab--hidden):first');
+      var $firstTab = this.details.siblings('.vertical-tabs__pane:not(.vertical-tab--hidden)').eq(0);
       if ($firstTab.length) {
         $firstTab.data('verticalTab').focus();
       }
diff --git a/core/modules/block/js/block.js b/core/modules/block/js/block.js
index 2b727c431965de3985c81ff599ae5fa035197421..3a42f37206bd35ac891c521642ccd35a64bac041 100644
--- a/core/modules/block/js/block.js
+++ b/core/modules/block/js/block.js
@@ -99,7 +99,7 @@
           tableDrag.rowObject = new tableDrag.row(row);
 
           // Find the correct region and insert the row as the last in the region.
-          table.find('.region-' + select[0].value + '-message').nextUntil('.region-message').last().before(row);
+          table.find('.region-' + select[0].value + '-message').nextUntil('.region-message').eq(-1).before(row);
 
           // Modify empty regions with added or removed fields.
           checkEmptyRegions(table, row);
diff --git a/core/modules/contextual/js/contextual.js b/core/modules/contextual/js/contextual.js
index e00b0118178fae9f2f62de602b5f6801a1867e33..1e27ec4102866f621a20dfbc831149dd62301b86 100644
--- a/core/modules/contextual/js/contextual.js
+++ b/core/modules/contextual/js/contextual.js
@@ -64,7 +64,7 @@
 
     // Create a model and the appropriate views.
     var model = new contextual.StateModel({
-      title: $region.find('h2:first').text().trim()
+      title: $region.find('h2').eq(0).text().trim()
     });
     var viewOptions = $.extend({el: $contextual, model: model}, options);
     contextual.views.push({
diff --git a/core/modules/editor/js/editor.formattedTextEditor.js b/core/modules/editor/js/editor.formattedTextEditor.js
index 75b20b65e093507b777dfb40fcb0ad32e873cec7..faf4a6d10f0ac02d6c6784d4e6cd0385404d6e87 100644
--- a/core/modules/editor/js/editor.formattedTextEditor.js
+++ b/core/modules/editor/js/editor.formattedTextEditor.js
@@ -41,7 +41,7 @@
 
       // Store the actual value of this field. We'll need this to restore the
       // original value when the user discards his modifications.
-      this.$textElement = this.$el.find('.field-item:first');
+      this.$textElement = this.$el.find('.field-item').eq(0);
       this.model.set('originalValue', this.$textElement.html());
     },
 
diff --git a/core/modules/text/text.js b/core/modules/text/text.js
index 0895415faf6c215935956faed91aabee12695a75..2ab1d0ae0af4179efc26d53ab8bcce010d4db12b 100644
--- a/core/modules/text/text.js
+++ b/core/modules/text/text.js
@@ -11,9 +11,9 @@
         var $widget = $(this).closest('.text-format-wrapper');
 
         var $summary = $widget.find('.text-summary-wrapper');
-        var $summaryLabel = $summary.find('label').first();
+        var $summaryLabel = $summary.find('label').eq(0);
         var $full = $widget.find('.text-full').closest('.form-item');
-        var $fullLabel = $full.find('label').first();
+        var $fullLabel = $full.find('label').eq(0);
 
         // Create a placeholder label when the field cardinality is greater
         // than 1.
diff --git a/core/modules/tour/js/tour.js b/core/modules/tour/js/tour.js
index f8bc85f452f1e814ad1396bcc0c23b192798f44f..8d85e105cb64ed0df8aa68da33a30cebae63cdf0 100644
--- a/core/modules/tour/js/tour.js
+++ b/core/modules/tour/js/tour.js
@@ -206,7 +206,7 @@
             $(this).find('.tour-progress').text(progress);
           })
           // Update the last item to have "End tour" as the button.
-          .last()
+          .eq(-1)
           .attr('data-text', Drupal.t('End tour'));
       }
     }
diff --git a/core/modules/views_ui/js/views-admin.js b/core/modules/views_ui/js/views-admin.js
index 236b746aad94391deb95da721b44091f68a185a5..7f217dc718200d912f46484059392eaa174f7441 100644
--- a/core/modules/views_ui/js/views-admin.js
+++ b/core/modules/views_ui/js/views-admin.js
@@ -241,7 +241,7 @@
       var $addDisplayDropdown = $('<li class="add"><a href="#"><span class="icon add"></span>' + Drupal.t('Add') + '</a><ul class="action-list" style="display:none;"></ul></li>');
       var $displayButtons = $menu.nextAll('input.add-display').detach();
       $displayButtons.appendTo($addDisplayDropdown.find('.action-list')).wrap('<li>')
-        .parent().first().addClass('first').end().last().addClass('last');
+        .parent().eq(0).addClass('first').end().eq(-1).addClass('last');
       // Remove the 'Add ' prefix from the button labels since they're being palced
       // in an 'Add' dropdown.
       // @todo This assumes English, but so does $addDisplayDropdown above. Add
@@ -701,7 +701,7 @@
         // Within the row, the operator labels are displayed inside the first table
         // cell (next to the filter name).
         var $draggableRow = $(this.draggableRows[i]);
-        var $firstCell = $draggableRow.find('td:first');
+        var $firstCell = $draggableRow.find('td').eq(0);
         if ($firstCell.length) {
           // The value of the operator label ("And" or "Or") is taken from the
           // first operator dropdown we encounter, going backwards from the current