diff --git a/test/openssl/test_ossl.rb b/test/openssl/test_ossl.rb
index 3a90ead10a..9f4b39d4f5 100644
--- a/test/openssl/test_ossl.rb
+++ b/test/openssl/test_ossl.rb
@@ -42,12 +42,6 @@ class OpenSSL::OSSL < OpenSSL::SSLTestCase
   end
 
   def test_memcmp_timing
-    begin
-      require "benchmark"
-    rescue LoadError
-      pend "Benchmark is not available in this environment. Please install it with `gem install benchmark`."
-    end
-
     # Ensure using fixed_length_secure_compare takes almost exactly the same amount of time to compare two different strings.
     # Regular string comparison will short-circuit on the first non-matching character, failing this test.
     # NOTE: this test may be susceptible to noise if the system running the tests is otherwise under load.
@@ -58,8 +52,14 @@ class OpenSSL::OSSL < OpenSSL::SSLTestCase
 
     a_b_time = a_c_time = 0
     100.times do
-      a_b_time += Benchmark.measure { 100.times { OpenSSL.fixed_length_secure_compare(a, b) } }.real
-      a_c_time += Benchmark.measure { 100.times { OpenSSL.fixed_length_secure_compare(a, c) } }.real
+      t1 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+      100.times { OpenSSL.fixed_length_secure_compare(a, b) }
+      t2 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+      100.times { OpenSSL.fixed_length_secure_compare(a, c) }
+      t3 = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+
+      a_b_time += t2 - t1
+      a_c_time += t3 - t2
     end
     assert_operator(a_b_time, :<, a_c_time * 10, "fixed_length_secure_compare timing test failed")
     assert_operator(a_c_time, :<, a_b_time * 10, "fixed_length_secure_compare timing test failed")