diff --git a/configure b/configure
index 18c5005..908fc09 100755
--- a/configure
+++ b/configure
@@ -4746,6 +4746,7 @@ $as_echo_n "checking whether openssl is usable... " >&6; }
 
 
 				#include <openssl/ssl.h>
+				#include <openssl/dh.h>
 
 int
 main ()
diff --git a/configure.ac b/configure.ac
index c94833e..b46a53d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -368,6 +368,7 @@ 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* ssl = SSL_new(ctx);
diff --git a/src/Utils.cpp b/src/Utils.cpp
index cced568..425831a 100644
--- 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>
diff --git a/src/main.cpp b/src/main.cpp
index 7d4e209..8d458a9 100644
--- 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);
diff --git a/third_party/Csocket/Csocket.cc b/third_party/Csocket/Csocket.cc
index 46a3bfd..017d22f 100644
--- 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