--- a/SWIG/_bio.i
+++ b/SWIG/_bio.i
@@ -63,14 +63,14 @@ extern BIO *BIO_pop(BIO *);
 static PyObject *_bio_err;
 
 
-#if OPENSSL_VERSION_NUMBER >= 0x10100000L
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER)
 void pyfd_init(void);
 #endif
 
 void bio_init(PyObject *bio_err) {
     Py_INCREF(bio_err);
     _bio_err = bio_err;
-#if OPENSSL_VERSION_NUMBER >= 0x10100000L
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER)
     pyfd_init();
 #endif
 }
@@ -299,7 +299,7 @@ int bio_should_write(BIO* a) {
     return BIO_should_write(a);
 }
 
-#if OPENSSL_VERSION_NUMBER >= 0x10100000L
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER)
 /* implment custom BIO_s_pyfd */
 
 #ifdef WIN32

--- a/SWIG/_evp.i
+++ b/SWIG/_evp.i
@@ -19,7 +19,7 @@ Copyright (c) 2009-2010 Heikki Toivonen. All rights reserved.
 #include <openssl/rsa.h>
 #include <openssl/opensslv.h>
 
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
 
 HMAC_CTX *HMAC_CTX_new(void) {
     HMAC_CTX *ret = PyMem_Malloc(sizeof(HMAC_CTX));

--- a/SWIG/_lib.i
+++ b/SWIG/_lib.i
@@ -18,7 +18,7 @@
 
 %{
 /* OpenSSL 1.0.2 copmatbility shim */
-#if OPENSSL_VERSION_NUMBER < 0x10002000L
+#if OPENSSL_VERSION_NUMBER < 0x10002000L || defined(LIBRESSL_VERSION_NUMBER)
 typedef void (*OPENSSL_sk_freefunc)(void *);
 typedef void *(*OPENSSL_sk_copyfunc)(const void *);
 typedef struct stack_st OPENSSL_STACK;
@@ -501,7 +501,7 @@ int passphrase_callback(char *buf, int num, int v, void *arg) {
 %inline %{
 
 void lib_init() {
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
     SSLeay_add_all_algorithms();
     ERR_load_ERR_strings();
 #endif

--- a/SWIG/_lib11_compat.i
+++ b/SWIG/_lib11_compat.i
@@ -8,7 +8,7 @@
  */
 
 %{
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
 
 #include <string.h>
 #include <openssl/engine.h>

--- a/SWIG/_ssl.i
+++ b/SWIG/_ssl.i
@@ -268,7 +268,7 @@ void ssl_init(PyObject *ssl_err, PyObject *ssl_timeout_err) {
 
 #ifndef OPENSSL_NO_SSL3
 const SSL_METHOD *sslv3_method(void) {
-#if OPENSSL_VERSION_NUMBER >= 0x10100000L
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER)
     PyErr_WarnEx(PyExc_DeprecationWarning,
                  "Function SSLv3_method has been deprecated.", 1);
 #endif
@@ -277,7 +277,7 @@ const SSL_METHOD *sslv3_method(void) {
 #endif
 
 const SSL_METHOD *tlsv1_method(void) {
-#if OPENSSL_VERSION_NUMBER >= 0x10100000L
+#if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER)
     PyErr_WarnEx(PyExc_DeprecationWarning,
                  "Function TLSv1_method has been deprecated.", 1);
 #endif

--- a/SWIG/_threads.i
+++ b/SWIG/_threads.i
@@ -5,7 +5,7 @@
 #include <pythread.h>
 #include <openssl/crypto.h>
 
-#if defined(THREADING) && OPENSSL_VERSION_NUMBER < 0x10100000L
+#if defined(THREADING) && OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
 #define CRYPTO_num_locks()      (CRYPTO_NUM_LOCKS)
 static PyThread_type_lock lock_cs[CRYPTO_num_locks()];
 static long lock_count[CRYPTO_num_locks()];
@@ -13,7 +13,7 @@ static int thread_mode = 0;
 #endif
 
 void threading_locking_callback(int mode, int type, const char *file, int line) {
-#if defined(THREADING) && OPENSSL_VERSION_NUMBER < 0x10100000L
+#if defined(THREADING) && OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
         if (mode & CRYPTO_LOCK) {
                 PyThread_acquire_lock(lock_cs[type], WAIT_LOCK);
                 lock_count[type]++;
@@ -25,7 +25,7 @@ void threading_locking_callback(int mode, int type, const char *file, int line)
 }
 
 unsigned long threading_id_callback(void) {
-#if defined(THREADING) && OPENSSL_VERSION_NUMBER < 0x10100000L
+#if defined(THREADING) && OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
     return (unsigned long)PyThread_get_thread_ident();
 #else
     return (unsigned long)0;
@@ -35,7 +35,7 @@ unsigned long threading_id_callback(void) {
 
 %inline %{
 void threading_init(void) {
-#if defined(THREADING) && OPENSSL_VERSION_NUMBER < 0x10100000L
+#if defined(THREADING) && OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
     int i;
     if (!thread_mode) {
         for (i=0; i<CRYPTO_num_locks(); i++) {
@@ -50,7 +50,7 @@ void threading_init(void) {
 }
 
 void threading_cleanup(void) {
-#if defined(THREADING) && OPENSSL_VERSION_NUMBER < 0x10100000L
+#if defined(THREADING) && OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
     int i;
     if (thread_mode) {
         CRYPTO_set_locking_callback(NULL);

--- a/SWIG/libcrypto-compat.h
+++ b/SWIG/libcrypto-compat.h
@@ -1,7 +1,7 @@
 #ifndef LIBCRYPTO_COMPAT_H
 #define LIBCRYPTO_COMPAT_H
 
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
 
 #include <openssl/rsa.h>
 #include <openssl/dsa.h>