diff --git a/tests/Mockery/IsolatedMockeryTest.php b/tests/Mockery/IsolatedMockeryTest.php
index 7402aeb..2e573ad 100644
--- a/tests/Mockery/IsolatedMockeryTest.php
+++ b/tests/Mockery/IsolatedMockeryTest.php
@@ -4,6 +4,7 @@
 
 use Mockery;
 use PHPUnit\Framework\TestCase;
+use function usleep;
 
 class IsolatedMockeryTest extends TestCase
 {
diff --git a/tests/Mockery/MockeryTest.php b/tests/Mockery/MockeryTest.php
index c5f6e95..2293fd8 100644
--- a/tests/Mockery/MockeryTest.php
+++ b/tests/Mockery/MockeryTest.php
@@ -5,6 +5,7 @@
 use Mockery;
 use Mockery\MockInterface;
 use PHPUnit\Framework\TestCase;
+use function usleep;
 
 class MockeryTest extends TestCase
 {