diff --git a/packages/html-reporter/src/chip.tsx b/packages/html-reporter/src/chip.tsx
index 537c439eb0..0965a40888 100644
--- a/packages/html-reporter/src/chip.tsx
+++ b/packages/html-reporter/src/chip.tsx
@@ -30,10 +30,12 @@ export const Chip: React.FC<{
   dataTestId?: string,
   targetRef?: React.RefObject<HTMLDivElement>,
 }> = ({ header, expanded, setExpanded, children, noInsets, dataTestId, targetRef }) => {
+  const id = React.useId();
   return <div className='chip' data-testid={dataTestId} ref={targetRef}>
     <div
       role='button'
       aria-expanded={!!expanded}
+      aria-controls={id}
       className={clsx('chip-header', setExpanded && ' expanded-' + expanded)}
       onClick={() => setExpanded?.(!expanded)}
       title={typeof header === 'string' ? header : undefined}>
@@ -41,7 +43,7 @@ export const Chip: React.FC<{
       {setExpanded && !expanded && icons.rightArrow()}
       {header}
     </div>
-    {(!setExpanded || expanded) && <div role='region' className={clsx('chip-body', noInsets && 'chip-body-no-insets')}>{children}</div>}
+    {(!setExpanded || expanded) && <div id={id} role='region' className={clsx('chip-body', noInsets && 'chip-body-no-insets')}>{children}</div>}
   </div>;
 };
 
diff --git a/packages/web/src/components/expandable.tsx b/packages/web/src/components/expandable.tsx
index 01e064373f..a837bd0a0c 100644
--- a/packages/web/src/components/expandable.tsx
+++ b/packages/web/src/components/expandable.tsx
@@ -24,14 +24,20 @@ export const Expandable: React.FunctionComponent<React.PropsWithChildren<{
   expanded: boolean,
   expandOnTitleClick?: boolean,
 }>> = ({ title, children, setExpanded, expanded, expandOnTitleClick }) => {
+  const id = React.useId();
   return <div className={clsx('expandable', expanded && 'expanded')}>
-    <div className='expandable-title' onClick={() => expandOnTitleClick && setExpanded(!expanded)}>
+    <div
+      role='button'
+      aria-expanded={expanded}
+      aria-controls={id}
+      className='expandable-title'
+      onClick={() => expandOnTitleClick && setExpanded(!expanded)}>
       <div
         className={clsx('codicon', expanded ? 'codicon-chevron-down' : 'codicon-chevron-right')}
         style={{ cursor: 'pointer', color: 'var(--vscode-foreground)', marginLeft: '5px' }}
         onClick={() => !expandOnTitleClick && setExpanded(!expanded)} />
       {title}
     </div>
-    { expanded && <div style={{ marginLeft: 25 }}>{children}</div> }
+    { expanded && <div id={id} role='region' style={{ marginLeft: 25 }}>{children}</div> }
   </div>;
 };
diff --git a/packages/web/src/components/treeView.tsx b/packages/web/src/components/treeView.tsx
index cb7ab7150d..e6cf557e99 100644
--- a/packages/web/src/components/treeView.tsx
+++ b/packages/web/src/components/treeView.tsx
@@ -231,6 +231,7 @@ export function TreeItemHeader<T extends TreeItem>({
   icon,
   isKeyboardNavigation,
   setIsKeyboardNavigation }: TreeItemHeaderProps<T>) {
+  const groupId = React.useId();
   const itemRef = React.useRef(null);
 
   React.useEffect(() => {
@@ -251,7 +252,7 @@ export function TreeItemHeader<T extends TreeItem>({
   const titled = title?.(item);
   const iconed = icon?.(item) || 'codicon-blank';
 
-  return <div ref={itemRef} role='treeitem' aria-selected={item === selectedItem} aria-expanded={expanded} title={titled} className='vbox' style={{ flex: 'none' }}>
+  return <div ref={itemRef} role='treeitem' aria-selected={item === selectedItem} aria-expanded={expanded} aria-controls={groupId} title={titled} className='vbox' style={{ flex: 'none' }}>
     <div
       onDoubleClick={() => onAccepted?.(item)}
       className={clsx(
@@ -281,7 +282,7 @@ export function TreeItemHeader<T extends TreeItem>({
       {icon && <div className={'codicon ' + iconed} style={{ minWidth: 16, marginRight: 4 }} aria-label={'[' + iconed.replace('codicon', 'icon') + ']'}></div>}
       {typeof rendered === 'string' ? <div style={{ textOverflow: 'ellipsis', overflow: 'hidden' }}>{rendered}</div> : rendered}
     </div>
-    {!!children.length && <div role='group'>
+    {!!children.length && <div id={groupId} role='group'>
       {children.map(child => {
         const itemData = treeItems.get(child);
         return itemData && <TreeItemHeader