diff --git a/tests/Unit/Crypt/RSA/ModeTest.php b/tests/Unit/Crypt/RSA/ModeTest.php
index 2763df29..854f9082 100644
--- a/tests/Unit/Crypt/RSA/ModeTest.php
+++ b/tests/Unit/Crypt/RSA/ModeTest.php
@@ -6,6 +6,7 @@
  */
 
 use phpseclib\Crypt\RSA;
+use phpseclib\Math\BigInteger;
 
 class Unit_Crypt_RSA_ModeTest extends PhpseclibTestCase
 {