diff -u -r ../httping-2.5/mssl.c ./mssl.c
--- ../httping-2.5/mssl.c	2016-09-12 07:45:50.000000000 +0000
+++ ./mssl.c	2018-08-23 19:38:43.467717597 +0000
@@ -35,7 +35,9 @@
 	ERR_free_strings();
 
 	ERR_remove_state(0);
+#ifndef OPENSSL_NO_ENGINE
 	ENGINE_cleanup();
+#endif
 	CONF_modules_free();
 	EVP_cleanup();
 	CRYPTO_cleanup_all_ex_data();