diff --git a/crypto/bf/bftest.c b/crypto/bf/bftest.c
index 24d526b14..14bc4d7c8 100644
--- a/crypto/bf/bftest.c
+++ b/crypto/bf/bftest.c
@@ -62,6 +62,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <openssl/opensslconf.h> /* To see if OPENSSL_NO_BF is defined */
 
 #include "../e_os.h"