diff --git a/app/views/admin/site_customization/content_blocks/edit.html.erb b/app/views/admin/site_customization/content_blocks/edit.html.erb
index 5fa818c7d..bdc15f1f8 100644
--- a/app/views/admin/site_customization/content_blocks/edit.html.erb
+++ b/app/views/admin/site_customization/content_blocks/edit.html.erb
@@ -9,6 +9,7 @@
   @content_block,
   text: t("admin.site_customization.content_blocks.index.delete"),
   path: (@is_heading_content_block ? admin_site_customization_delete_heading_content_block_path(@content_block.id) : admin_site_customization_content_block_path(@content_block)),
+  confirm: true,
   method: :delete,
   class: "delete float-right"
 ) %>
diff --git a/spec/system/admin/site_customization/content_blocks_spec.rb b/spec/system/admin/site_customization/content_blocks_spec.rb
index 42c125769..abbefc138 100644
--- a/spec/system/admin/site_customization/content_blocks_spec.rb
+++ b/spec/system/admin/site_customization/content_blocks_spec.rb
@@ -103,7 +103,9 @@ describe "Admin custom content blocks", :admin do
       block = create(:site_customization_content_block)
       visit edit_admin_site_customization_content_block_path(block)
 
-      click_button "Delete block"
+      accept_confirm("Are you sure? This action will delete \"#{block.name}\" and can't be undone.") do
+        click_button "Delete block"
+      end
 
       expect(page).not_to have_content("#{block.name} (#{block.locale})")
       expect(page).not_to have_content(block.body)