diff --git a/lib/tasks/dev.rake b/lib/tasks/dev.rake
index 69b3f6344eb..4cbb047a23b 100644
--- a/lib/tasks/dev.rake
+++ b/lib/tasks/dev.rake
@@ -146,7 +146,7 @@ namespace :dev do
                 else
                   success = true
                 end
-                sleep(usps_request_delay_ms / 1000.0) if usps_request_delay_ms
+                Kernel.sleep(usps_request_delay_ms / 1000.0) if usps_request_delay_ms
               end
             else
               enrollment = InPersonEnrollment.create!(
diff --git a/spec/lib/tasks/dev_rake_spec.rb b/spec/lib/tasks/dev_rake_spec.rb
index 1c0adbde17d..3fba0d4927b 100644
--- a/spec/lib/tasks/dev_rake_spec.rb
+++ b/spec/lib/tasks/dev_rake_spec.rb
@@ -330,7 +330,7 @@
       stub_request_token
       stub_request_enroll
 
-      expect_any_instance_of(Object).to receive(:sleep).exactly(10).times.with(0.2)
+      expect(Kernel).to receive(:sleep).exactly(10).times.with(0.2)
 
       Rake::Task['dev:random_in_person_users'].invoke
     end
@@ -436,7 +436,7 @@
         ).times(1)
       expect(UspsInPersonProofing::EnrollmentHelper).
         to receive(:schedule_in_person_enrollment).and_call_original.exactly(3).times
-      expect_any_instance_of(Object).to receive(:sleep).exactly(3).times.with(0.2)
+      expect(Kernel).to receive(:sleep).exactly(3).times.with(0.2)
 
       Rake::Task['dev:random_in_person_users'].invoke
     end