diff --git a/ssl/test/async_bio.cc b/ssl/test/async_bio.cc
index fd35176..89d66d7 100644
--- a/ssl/test/async_bio.cc
+++ b/ssl/test/async_bio.cc
@@ -102,7 +102,7 @@
     return 0;
   }
   BIO_clear_retry_flags(bio);
-  int ret = BIO_ctrl(bio->next_bio, cmd, num, ptr);
+  long ret = BIO_ctrl(bio->next_bio, cmd, num, ptr);
   BIO_copy_next_retry(bio);
   return ret;
 }