diff --git a/test/middleware/retry_test.rb b/test/middleware/retry_test.rb
index 3f91017b..6756f577 100644
--- a/test/middleware/retry_test.rb
+++ b/test/middleware/retry_test.rb
@@ -85,11 +85,17 @@ module Middleware
 
     def test_random_additional_interval_amount
       middleware = Faraday::Request::Retry.new(nil, :max => 2, :interval => 0.1, :interval_randomness => 100)
-      assert middleware.sleep_amount(2).between?(0.1, 0.2)
+      sleep_amount = middleware.sleep_amount(2)
+      assert_operator sleep_amount, :>=, 0.1
+      assert_operator sleep_amount, :<=, 0.2
       middleware = Faraday::Request::Retry.new(nil, :max => 2, :interval => 0.1, :interval_randomness => 50)
-      assert middleware.sleep_amount(2).between?(0.1, 0.15)
+      sleep_amount = middleware.sleep_amount(2)
+      assert_operator sleep_amount, :>=, 0.1
+      assert_operator sleep_amount, :<=, 0.15
       middleware = Faraday::Request::Retry.new(nil, :max => 2, :interval => 0.1, :interval_randomness => 25)
-      assert middleware.sleep_amount(2).between?(0.1, 0.125)
+      sleep_amount = middleware.sleep_amount(2)
+      assert_operator sleep_amount, :>=, 0.1
+      assert_operator sleep_amount, :<=, 0.125
     end
 
     def test_custom_exceptions