diff --git a/src/Backend/OpenSSL.php b/src/Backend/OpenSSL.php
index 1221e889..1fffc52a 100644
--- a/src/Backend/OpenSSL.php
+++ b/src/Backend/OpenSSL.php
@@ -22,7 +22,6 @@
 use function openssl_verify;
 use function ord;
 use function str_repeat;
-use function strval;
 use function substr;
 
 /**