diff --git a/wolfssl/openssl/bio.h b/wolfssl/openssl/bio.h
index 7f3816cb5..7fd42b890 100644
--- a/wolfssl/openssl/bio.h
+++ b/wolfssl/openssl/bio.h
@@ -39,6 +39,7 @@
 
 #define BIO_TYPE_FILE WOLFSSL_BIO_FILE
 #define BIO_TYPE_BIO  WOLFSSL_BIO_BIO
+#define BIO_TYPE_MEM  WOLFSSL_BIO_MEMORY
 
 
 #ifdef __cplusplus