diff --git a/spec/mailers/previews/user_mailer_preview_spec.rb b/spec/mailers/previews/user_mailer_preview_spec.rb
index f0ae9d81b88..e82fd5c6e38 100644
--- a/spec/mailers/previews/user_mailer_preview_spec.rb
+++ b/spec/mailers/previews/user_mailer_preview_spec.rb
@@ -4,8 +4,17 @@
 RSpec.describe UserMailerPreview do
   UserMailerPreview.instance_methods(false).each do |mailer_method|
     describe "##{mailer_method}" do
+      subject(:mail) { UserMailerPreview.new.public_send(mailer_method) }
+
       it 'generates a preview without blowing up' do
-        expect { UserMailerPreview.new.public_send(mailer_method).body }.to_not raise_error
+        expect { mail.body }.to_not raise_error
+      end
+
+      it 'does not include any svg images' do
+        # SVGs are typically the preferred format for their high-quality and small file size, but
+        # they are not well-supported in email clients. Instead, store a rasterized version of the
+        # image in `app/assets/images/email` for use in mailer content.
+        expect(mail.html_part.body).not_to have_selector("img[src$='.svg']")
       end
     end
   end