diff --git a/core/flyout_base.ts b/core/flyout_base.ts
index 7caf98c9b..8d4264f46 100644
--- a/core/flyout_base.ts
+++ b/core/flyout_base.ts
@@ -338,6 +338,9 @@ export abstract class Flyout
   init(targetWorkspace: WorkspaceSvg) {
     this.targetWorkspace = targetWorkspace;
     this.workspace_.targetWorkspace = targetWorkspace;
+    if (this.targetWorkspace.isMutator) {
+      aria.setRole(this.workspace_.getFocusableElement(), aria.Role.GENERIC);
+    }
 
     this.workspace_.scrollbar = new ScrollbarPair(
       this.workspace_,
diff --git a/core/utils/aria.ts b/core/utils/aria.ts
index 84d4e2312..64d1bf143 100644
--- a/core/utils/aria.ts
+++ b/core/utils/aria.ts
@@ -54,6 +54,7 @@ export enum Role {
   COMBOBOX = 'combobox',
   SPINBUTTON = 'spinbutton',
   REGION = 'region',
+  GENERIC = 'generic',
 }
 
 /**
diff --git a/core/workspace_svg.ts b/core/workspace_svg.ts
index e09618bb9..b919fa5c7 100644
--- a/core/workspace_svg.ts
+++ b/core/workspace_svg.ts
@@ -762,14 +762,19 @@ export class WorkspaceSvg
     });
 
     let ariaLabel = null;
+    let role: aria.Role | null = null;
     if (this.isFlyout) {
       ariaLabel = 'Flyout';
+      // Default to region, but this may change during flyout initialization.
+      role = aria.Role.REGION;
     } else if (this.isMutator) {
       ariaLabel = 'Mutator Workspace';
+      role = aria.Role.GENERIC;
     } else {
       ariaLabel = Msg['WORKSPACE_ARIA_LABEL'];
+      role = aria.Role.REGION;
     }
-    aria.setRole(this.svgGroup_, aria.Role.REGION);
+    aria.setRole(this.svgGroup_, role);
     aria.setState(this.svgGroup_, aria.State.LABEL, ariaLabel);
 
     // Note that a <g> alone does not receive mouse events--it must have a