diff --git a/web/viewer.html b/web/viewer.html
index 4845807c3cffab..afee3100d12b9e 100644
--- a/web/viewer.html
+++ b/web/viewer.html
@@ -332,10 +332,10 @@
                 <div class="verticalToolbarSeparator hiddenMediumView"></div>
 
                 <div id="editorModeButtons" class="splitToolbarButton toggled" role="radiogroup">
-                  <button id="editorFreeText" class="toolbarButton" disabled="disabled" title="Text" role="radio" aria-checked="false" tabindex="34" data-l10n-id="editor_free_text2">
+                  <button id="editorFreeText" class="toolbarButton" disabled="disabled" title="Text" role="radio" aria-checked="false" aria-controls="editorFreeTextParamsToolbar" tabindex="34" data-l10n-id="editor_free_text2">
                     <span data-l10n-id="editor_free_text2_label">Text</span>
                   </button>
-                  <button id="editorInk" class="toolbarButton" disabled="disabled" title="Draw" role="radio" aria-checked="false" tabindex="35" data-l10n-id="editor_ink2">
+                  <button id="editorInk" class="toolbarButton" disabled="disabled" title="Draw" role="radio" aria-checked="false" aria-controls="editorInkParamsToolbar" tabindex="35" data-l10n-id="editor_ink2">
                     <span data-l10n-id="editor_ink2_label">Draw</span>
                   </button>
                 </div>