diff --git a/src/Generator/DefaultTimeGenerator.php b/src/Generator/DefaultTimeGenerator.php
index 9733ed6..f05d818 100644
--- a/src/Generator/DefaultTimeGenerator.php
+++ b/src/Generator/DefaultTimeGenerator.php
@@ -79,7 +79,7 @@ class DefaultTimeGenerator implements TimeGeneratorInterface
 
         if ($clockSeq === null) {
             // Not using "stable storage"; see RFC 4122, Section 4.2.1.1
-            $clockSeq = mt_rand(0, 0x3fff);
+            $clockSeq = random_int(0, 0x3fff);
         }
 
         // Create a 60-bit time value as a count of 100-nanosecond intervals
diff --git a/tests/Generator/DefaultTimeGeneratorTest.php b/tests/Generator/DefaultTimeGeneratorTest.php
index 132c785..b12f6b5 100644
--- a/tests/Generator/DefaultTimeGeneratorTest.php
+++ b/tests/Generator/DefaultTimeGeneratorTest.php
@@ -166,7 +166,7 @@ class DefaultTimeGeneratorTest extends TestCase
     public function testGenerateUsesRandomSequenceWhenClockSeqNull()
     {
         $this->skipIfHhvm();
-        $mt_rand = AspectMock::func('Ramsey\Uuid\Generator', 'mt_rand', 9622);
+        $mt_rand = AspectMock::func('Ramsey\Uuid\Generator', 'random_int', 9622);
         $defaultTimeGenerator = new DefaultTimeGenerator(
             $this->nodeProvider,
             $this->timeConverter,