diff --git a/mesop/web/src/editor_toolbar/editor_toolbar.ng.html b/mesop/web/src/editor_toolbar/editor_toolbar.ng.html
index b8b316d6..ab2568bd 100644
--- a/mesop/web/src/editor_toolbar/editor_toolbar.ng.html
+++ b/mesop/web/src/editor_toolbar/editor_toolbar.ng.html
@@ -26,7 +26,8 @@
   </button>
   <textarea
     #textarea
-    placeholder="Type in the UI change you want..."
+    disabled="{{isLoading}}"
+    placeholder="{{isLoading ? 'Generating...' : 'Type in the UI change you want...' }}"
     class="floating-editor-toolbar-textarea"
     [(ngModel)]="prompt"
     (ngModelChange)="onPromptChange($event)"
@@ -50,9 +51,11 @@
     <span>{{responseTime | number:'1.1-1'}}s</span>
   </div>
   }
-  <button mat-icon-button class="send-button" (click)="sendPrompt()">
+
+  <button mat-icon-button (click)="sendPrompt()" [disabled]="isLoading">
     <mat-icon>send</mat-icon>
   </button>
+
   <button
     mat-icon-button
     (click)="openHistory()"
diff --git a/mesop/web/src/editor_toolbar/editor_toolbar_service.ts b/mesop/web/src/editor_toolbar/editor_toolbar_service.ts
index 30e9719e..352c2e0b 100644
--- a/mesop/web/src/editor_toolbar/editor_toolbar_service.ts
+++ b/mesop/web/src/editor_toolbar/editor_toolbar_service.ts
@@ -71,6 +71,9 @@ export class EditorToolbarService {
     sourceCodeLocation?: SourceCodeLocation | undefined,
   ): Promise<PromptResponse> {
     console.debug('sendPrompt', prompt);
+    if (this.eventSource) {
+      return Promise.reject(new Error('Prompt already in progress'));
+    }
     // Clear the progress subject
     this.generationProgressSubject.next('');
     const path = window.location.pathname;