diff --git a/accessible/field.component.js b/accessible/field.component.js
index 328736a6f..17af710f3 100644
--- a/accessible/field.component.js
+++ b/accessible/field.component.js
@@ -29,23 +29,23 @@ blocklyApp.FieldComponent = ng.core
     selector: 'blockly-field',
     template: `
     <li [id]="idMap['listItem']" role="treeitem" *ngIf="isTextInput()"
-        [attr.aria-level]="level" aria-selected="false">
+        [attr.aria-level]="level">
       <input [id]="idMap['input']" [ngModel]="field.getValue()" (ngModelChange)="field.setValue($event)"
              [disabled]="disabled" type="text" aria-label="string">
     </li>
     <li [id]="idMap['listItem']" role="treeitem" *ngIf="isNumberInput()"
-        [attr.aria-level]="level" aria-selected="false">
+        [attr.aria-level]="level">
       <input [id]="idMap['input']" [ngModel]="field.getValue()" (ngModelChange)="field.setValue($event)"
              [disabled]="disabled" type="number" aria-label="number">
     </li>
     <li [id]="idMap['listItem']" role="treeitem" *ngIf="isDropdown()"
         [attr.aria-labelledBy]="generateAriaLabelledByAttr('blockly-argument-menu', idMap['label'])"
-        [attr.aria-level]="level" aria-selected="false">
+        [attr.aria-level]="level">
       <label [id]="idMap['label']">{{'CURRENT_ARGUMENT_VALUE'|translate}} {{field.getText()}}</label>
       <ol role="group">
         <li [id]="idMap[optionValue]" role="treeitem" *ngFor="#optionValue of getOptions()"
             [attr.aria-labelledBy]="generateAriaLabelledByAttr(idMap[optionValue + 'Button'], 'blockly-button')"
-            [attr.aria-level]="level + 1" aria-selected="false">
+            [attr.aria-level]="level + 1">
           <button [id]="idMap[optionValue + 'Button']" (click)="handleDropdownChange(field, optionValue)"
                   [disabled]="disabled">
             {{optionText[optionValue]}}
@@ -54,12 +54,12 @@ blocklyApp.FieldComponent = ng.core
       </ol>
     </li>
     <li [id]="idMap['listItem']" role="treeitem" *ngIf="isCheckbox()"
-        [attr.aria-level]="level" aria-selected="false">
+        [attr.aria-level]="level">
       // Checkboxes are not currently supported.
     </li>
     <li [id]="idMap['listItem']" role="treeitem" *ngIf="isTextField() && hasVisibleText()"
         [attr.aria-labelledBy]="utilsService.generateAriaLabelledByAttr('blockly-argument-text', idMap['label'])"
-        [attr.aria-level]="level" aria-selected="false">
+        [attr.aria-level]="level">
       <label [id]="idMap['label']">
         {{field.getText()}}
       </label>
diff --git a/accessible/toolbox-tree.component.js b/accessible/toolbox-tree.component.js
index e0d13424f..42449e4a9 100644
--- a/accessible/toolbox-tree.component.js
+++ b/accessible/toolbox-tree.component.js
@@ -31,19 +31,18 @@ blocklyApp.ToolboxTreeComponent = ng.core
     <li #parentList [id]="idMap['parentList']" role="treeitem"
         [ngClass]="{blocklyHasChildren: displayBlockMenu || block.inputList.length > 0, blocklyActiveDescendant: index == 0 && noCategories}"
         [attr.aria-labelledBy]="generateAriaLabelledByAttr('blockly-block-summary', idMap['blockSummaryLabel'])"
-        [attr.aria-selected]="index == 0 && tree.getAttribute('aria-activedescendant') == 'blockly-toolbox-tree-node0'"
         [attr.aria-level]="level">
       <label #blockSummaryLabel [id]="idMap['blockSummaryLabel']">{{block.toString()}}</label>
       <ol role="group" *ngIf="displayBlockMenu || block.inputList.length > 0">
         <li #listItem class="blocklyHasChildren" [id]="idMap['listItem']"
             [attr.aria-labelledBy]="generateAriaLabelledByAttr('blockly-block-menu', idMap['blockSummaryLabel'])"
             *ngIf="displayBlockMenu" role="treeitem"
-            aria-selected="false" [attr.aria-level]="level + 1">
+            [attr.aria-level]="level + 1">
           <label #label [id]="idMap['label']">{{'BLOCK_ACTION_LIST'|translate}}</label>
           <ol role="group" *ngIf="displayBlockMenu">
             <li #workspaceCopy [id]="idMap['workspaceCopy']" role="treeitem"
                 [attr.aria-labelledBy]="generateAriaLabelledByAttr(idMap['workspaceCopyButton'], 'blockly-button')"
-                [attr.aria-level]="level + 2" aria-selected="false">
+                [attr.aria-level]="level + 2">
               <button #workspaceCopyButton [id]="idMap['workspaceCopyButton']"
                       (click)="copyToWorkspace()">
                 {{'COPY_TO_WORKSPACE'|translate}}
@@ -51,7 +50,7 @@ blocklyApp.ToolboxTreeComponent = ng.core
             </li>
             <li #blockCopy [id]="idMap['blockCopy']" role="treeitem"
                 [attr.aria-labelledBy]="generateAriaLabelledByAttr(idMap['blockCopyButton'], 'blockly-button')"
-                [attr.aria-level]="level + 2" aria-selected="false">
+                [attr.aria-level]="level + 2">
               <button #blockCopyButton
                       [id]="idMap['blockCopyButton']"
                       (click)="copyToClipboard()">
@@ -60,7 +59,7 @@ blocklyApp.ToolboxTreeComponent = ng.core
             </li>
             <li #sendToSelected [id]="idMap['sendToSelected']" role="treeitem"
                 [attr.aria-labelledBy]="generateAriaLabelledByAttr(idMap['sendToSelectedButton'], 'blockly-button', !canBeCopiedToMarkedConnection())"
-                [attr.aria-level]="level + 2" aria-selected="false">
+                [attr.aria-level]="level + 2">
               <button #sendToSelectedButton
                       [id]="idMap['sendToSelectedButton']"
                       (click)="copyToMarkedSpot()"
@@ -82,7 +81,7 @@ blocklyApp.ToolboxTreeComponent = ng.core
           <li #listItem1 [id]="idMap['listItem' + i]" role="treeitem"
               *ngIf="inputBlock.connection && !inputBlock.connection.targetBlock()"
               [attr.aria-labelledBy]="generateAriaLabelledByAttr('blockly-argument-text', idMap['listItem' + i + 'Label'])"
-              [attr.aria-level]="level + 1" aria-selected="false">
+              [attr.aria-level]="level + 1">
             <!--TODO(madeeha): i18n here will need to happen in a different way due to the way grammar changes based on language.-->
             <label #label [id]="idMap['listItem' + i + 'Label']">
               {{utilsService.getInputTypeLabel(inputBlock.connection)}}
diff --git a/accessible/toolbox.component.js b/accessible/toolbox.component.js
index 5319f4d50..5e2418417 100644
--- a/accessible/toolbox.component.js
+++ b/accessible/toolbox.component.js
@@ -39,7 +39,7 @@ blocklyApp.ToolboxComponent = ng.core
               [id]="idMap['Parent' + i]" role="treeitem"
               [ngClass]="{blocklyHasChildren: true, blocklyActiveDescendant: tree.getAttribute('aria-activedescendant') == idMap['Parent' + i]}"
               *ngFor="#category of toolboxCategories; #i=index"
-              aria-level="1" aria-selected="false"
+              aria-level="1"
               [attr.aria-label]="category.attributes.name.value">
             <div *ngIf="category && category.attributes">
               <label [id]="idMap['Label' + i]" #name>
diff --git a/accessible/tree.service.js b/accessible/tree.service.js
index 077d062a7..f0e6c8710 100644
--- a/accessible/tree.service.js
+++ b/accessible/tree.service.js
@@ -107,13 +107,11 @@ blocklyApp.TreeService = ng.core
       var activeDesc = document.getElementById(activeDescId);
       if (activeDesc) {
         activeDesc.classList.remove('blocklyActiveDescendant');
-        activeDesc.setAttribute('aria-selected', 'false');
       }
     },
     markActiveDesc_: function(activeDescId) {
       var newActiveDesc = document.getElementById(activeDescId);
       newActiveDesc.classList.add('blocklyActiveDescendant');
-      newActiveDesc.setAttribute('aria-selected', 'true');
     },
     // Runs the given function while preserving the focus and active descendant
     // for the given tree.
diff --git a/accessible/workspace-tree.component.js b/accessible/workspace-tree.component.js
index 996117d36..f0dd60916 100644
--- a/accessible/workspace-tree.component.js
+++ b/accessible/workspace-tree.component.js
@@ -30,19 +30,19 @@ blocklyApp.WorkspaceTreeComponent = ng.core
     template: `
     <li [id]="idMap['blockRoot']" role="treeitem" class="blocklyHasChildren"
         [attr.aria-labelledBy]="generateAriaLabelledByAttr('blockly-block-summary', idMap['blockSummary'])"
-        [attr.aria-level]="level" aria-selected="false">
+        [attr.aria-level]="level">
       <label [id]="idMap['blockSummary']">{{block.toString()}}</label>
 
       <ol role="group">
         <li [id]="idMap['listItem']" class="blocklyHasChildren" role="treeitem"
             [attr.aria-labelledBy]="generateAriaLabelledByAttr('blockly-block-menu', idMap['blockSummary'])"
-            [attr.aria-level]="level + 1" aria-selected="false">
+            [attr.aria-level]="level + 1">
           <label [id]="idMap['label']">{{'BLOCK_ACTION_LIST'|translate}}</label>
           <ol role="group">
             <li *ngFor="#buttonInfo of actionButtonsInfo"
                 [id]="idMap[buttonInfo.baseIdKey]" role="treeitem"
                 [attr.aria-labelledBy]="generateAriaLabelledByAttr(idMap[buttonInfo.baseIdKey + 'Button'], 'blockly-button', buttonInfo.isDisabled())"
-                [attr.aria-level]="level + 2" aria-selected="false">
+                [attr.aria-level]="level + 2">
               <button [id]="idMap[buttonInfo.baseIdKey + 'Button']" (click)="buttonInfo.action()"
                       [disabled]="buttonInfo.isDisabled()">
                 {{buttonInfo.translationIdForText|translate}}
@@ -65,7 +65,7 @@ blocklyApp.WorkspaceTreeComponent = ng.core
             <ol role="group">
               <li [id]="idMap['markSpot' + i]" role="treeitem" *ngFor="#fieldButtonInfo of fieldButtonsInfo"
                   [attr.aria-labelledBy]="generateAriaLabelledByAttr(idMap[fieldButtonInfo.baseIdKey + 'Button'], 'blockly-button', fieldButtonInfo.isDisabled(inputBlock.connection))"
-                  [attr.aria-level]="level + 2" aria-selected="false">
+                  [attr.aria-level]="level + 2">
                 <button [id]="idMap[fieldButtonInfo.baseIdKey + 'Button']" (click)="fieldButtonInfo.action(inputBlock.connection)">
                   {{fieldButtonInfo.translationIdForText|translate}}
                 </button>