diff --git a/test/generators/suspenders/install/web_generator_test.rb b/test/generators/suspenders/install/web_generator_test.rb
index b2740732..8e9ff1b0 100644
--- a/test/generators/suspenders/install/web_generator_test.rb
+++ b/test/generators/suspenders/install/web_generator_test.rb
@@ -52,6 +52,10 @@ class WebGeneratorTest < Rails::Generators::TestCase
 
         def prepare_destination
           touch "Gemfile"
+
+          File.open("test/dummy/Gemfile", "w") do |f|
+            f.write('source "https://rubygems.org"')
+          end
         end
 
         def restore_destination