diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 5d22d02..22c3f99 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4444,6 +4444,17 @@
             ret = MBEDTLS_ERR_SSL_CA_CHAIN_REQUIRED;
         }
 
+#if defined(MBEDTLS_DEBUG_C)
+        if( ssl->session_negotiate->verify_result != 0 )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 3, ( "! Certificate verification flags %x",
+                                        ssl->session_negotiate->verify_result ) );
+        }
+        else
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 3, ( "Certificate verification flags clear" ) );
+        }
+#endif /* MBEDTLS_DEBUG_C */
     }
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate" ) );