diff -ur nginx/src/event/ngx_event_openssl.c nginx-debug/src/event/ngx_event_openssl.c
--- nginx/src/event/ngx_event_openssl.c	2019-10-29 17:31:13.468021354 +0100
+++ nginx-debug/src/event/ngx_event_openssl.c	2019-10-29 17:31:06.152106826 +0100
@@ -164,6 +164,11 @@
 
 #endif
 
+#ifdef WOLFSSL_NGINX
+    /* Turn on internal wolfssl debugging to stdout */
+    wolfSSL_Debugging_ON();
+#endif
+
 #if OPENSSL_VERSION_NUMBER >= 0x0090800fL
 #ifndef SSL_OP_NO_COMPRESSION
     {