diff --git a/google-cloud-debugger/test/google/cloud/debugger/backoff_test.rb b/google-cloud-debugger/test/google/cloud/debugger/backoff_test.rb
index <HASH>..<HASH> 100644
--- a/google-cloud-debugger/test/google/cloud/debugger/backoff_test.rb
+++ b/google-cloud-debugger/test/google/cloud/debugger/backoff_test.rb
@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+require "helper"
 
 describe Google::Cloud::Debugger::Backoff do
   let(:backoff) { Google::Cloud::Debugger::Backoff.new }
Fix intermittent debugger backoff test failures (#<I>)