--- a/configure.ac
+++ b/configure.ac
@@ -368,8 +368,9 @@ if test "x$SSL" != "xno"; then
 		AC_LINK_IFELSE([
 			AC_LANG_PROGRAM([[
 				#include <openssl/ssl.h>
+				#include <openssl/dh.h>
 			]], [[
-				SSL_CTX* ctx = SSL_CTX_new(TLSv1_method());
+				SSL_CTX* ctx = SSL_CTX_new(SSLv23_method());
 				SSL* ssl = SSL_new(ctx);
 				DH* dh = DH_new();
 				DH_free(dh);
--- a/include/znc/Utils.h
+++ b/include/znc/Utils.h
@@ -219,6 +219,11 @@ class CTable : protected std::vector<std::vector<CString>> {
 #include <openssl/aes.h>
 #include <openssl/blowfish.h>
 #include <openssl/md5.h>
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#define X509_getm_notBefore X509_get_notBefore
+#define X509_getm_notAfter X509_get_notAfter
+#endif
+
 //! does Blowfish w/64 bit feedback, no padding
 class CBlowfish {
   public:
--- a/src/Utils.cpp
+++ b/src/Utils.cpp
@@ -27,6 +27,8 @@
 #include <znc/Message.h>
 #ifdef HAVE_LIBSSL
 #include <openssl/ssl.h>
+#include <openssl/bn.h>
+#include <openssl/rsa.h>
 #endif /* HAVE_LIBSSL */
 #include <memory>
 #include <unistd.h>
@@ -93,8 +95,8 @@ void CUtils::GenerateCert(FILE* pOut, const CString& sHost) {
 
     X509_set_version(pCert.get(), 2);
     ASN1_INTEGER_set(X509_get_serialNumber(pCert.get()), serial);
-    X509_gmtime_adj(X509_get_notBefore(pCert.get()), 0);
-    X509_gmtime_adj(X509_get_notAfter(pCert.get()),
+    X509_gmtime_adj(X509_getm_notBefore(pCert.get()), 0);
+    X509_gmtime_adj(X509_getm_notAfter(pCert.get()),
                     (long)60 * 60 * 24 * days * years);
     X509_set_pubkey(pCert.get(), pKey.get());
 
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -46,8 +46,8 @@ static void locking_callback(int mode, int type, const char* file, int line) {
     }
 }
 
-static unsigned long thread_id_callback() {
-    return (unsigned long)pthread_self();
+static void thread_id_callback(CRYPTO_THREADID *id) {
+    CRYPTO_THREADID_set_numeric(id, (unsigned long)pthread_self());
 }
 
 static CRYPTO_dynlock_value* dyn_create_callback(const char* file, int line) {
@@ -78,7 +78,7 @@ static void thread_setup() {
     for (std::unique_ptr<CMutex>& mtx : lock_cs)
         mtx = std::unique_ptr<CMutex>(new CMutex());
 
-    CRYPTO_set_id_callback(&thread_id_callback);
+    CRYPTO_THREADID_set_callback(&thread_id_callback);
     CRYPTO_set_locking_callback(&locking_callback);
 
     CRYPTO_set_dynlock_create_callback(&dyn_create_callback);
--- a/third_party/Csocket/Csocket.cc
+++ b/third_party/Csocket/Csocket.cc
@@ -47,10 +47,16 @@
 #include <stdio.h>
 #include <openssl/ssl.h>
 #include <openssl/conf.h>
-#include <openssl/engine.h>
+#include <openssl/bn.h>
+#include <openssl/dh.h>
+#include <openssl/dsa.h>
+#include <openssl/rsa.h>
 #ifndef OPENSSL_NO_COMP
 #include <openssl/comp.h>
 #endif
+#ifndef OPENSSL_NO_ENGINE
+#include <openssl/engine.h>
+#endif
 #define HAVE_ERR_REMOVE_STATE
 #ifdef OPENSSL_VERSION_NUMBER
 # if OPENSSL_VERSION_NUMBER >= 0x10000000
@@ -594,9 +600,11 @@ void ShutdownCsocket()
 #ifndef OPENSSL_IS_BORINGSSL
 	CONF_modules_unload( 1 );
 #endif
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
 	ERR_free_strings();
 	EVP_cleanup();
 	CRYPTO_cleanup_all_ex_data();
+#endif
 #endif /* HAVE_LIBSSL */
 #ifdef HAVE_C_ARES
 #if ARES_VERSION >= CREATE_ARES_VER( 1, 6, 1 )
@@ -611,12 +619,14 @@ void ShutdownCsocket()
 #ifdef HAVE_LIBSSL
 bool InitSSL( ECompType eCompressionType )
 {
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
 	SSL_load_error_strings();
 	if( SSL_library_init() != 1 )
 	{
 		CS_DEBUG( "SSL_library_init() failed!" );
 		return( false );
 	}
+#endif
 
 #ifndef _WIN32
 	if( access( "/dev/urandom", R_OK ) == 0 )