diff --git a/lib/vtls/vtls.h b/lib/vtls/vtls.h
index 2aabeda20..b4df04771 100644
--- a/lib/vtls/vtls.h
+++ b/lib/vtls/vtls.h
@@ -23,6 +23,39 @@
  ***************************************************************************/
 #include "curl_setup.h"
 
+struct connectdata;
+
+struct Curl_ssl {
+  const char *name;
+
+  int (*init)(void);
+  void (*cleanup)(void);
+
+  size_t (*version)(char *buffer, size_t size);
+  int (*check_cxn)(struct connectdata *cxn);
+  int (*shutdown)(struct connectdata *conn, int sockindex);
+  bool (*data_pending)(const struct connectdata *conn,
+                       int connindex);
+
+  /* return 0 if a find random is filled in */
+  CURLcode (*random)(struct Curl_easy *data, unsigned char *entropy,
+                     size_t length);
+  bool (*cert_status_request)(void);
+
+  CURLcode (*connect)(struct connectdata *conn, int sockindex);
+  CURLcode (*connect_nonblocking)(struct connectdata *conn, int sockindex,
+                                  bool *done);
+  void (*close)(struct connectdata *conn, int sockindex);
+  void (*close_all)(struct Curl_easy *data);
+  void (*session_free)(void *ptr);
+
+  CURLcode (*set_engine)(struct Curl_easy *data, const char *engine);
+  CURLcode (*set_engine_default)(struct Curl_easy *data);
+  struct curl_slist *(*engines_list)(struct Curl_easy *data);
+
+  bool (*false_start)(void);
+};
+
 #include "openssl.h"        /* OpenSSL versions */
 #include "gtls.h"           /* GnuTLS versions */
 #include "nssg.h"           /* NSS versions */