diff --git a/programs/ssl/ssl_client1.c b/programs/ssl/ssl_client1.c
index a902376..eefb099 100644
--- a/programs/ssl/ssl_client1.c
+++ b/programs/ssl/ssl_client1.c
@@ -157,6 +157,8 @@
     printf( " ok\n" );
 
     ssl_set_endpoint( &ssl, SSL_IS_CLIENT );
+    /* OPTIONAL is not optimal for security,
+     * but makes interop easier in this simplified example */
     ssl_set_authmode( &ssl, SSL_VERIFY_OPTIONAL );
     ssl_set_ca_chain( &ssl, &cacert, NULL, "PolarSSL Server 1" );
 
@@ -187,6 +189,7 @@
      */
     printf( "  . Verifying peer X.509 certificate..." );
 
+    /* In real life, we may want to bail out when ret != 0 */
     if( ( ret = ssl_get_verify_result( &ssl ) ) != 0 )
     {
         printf( " failed\n" );
diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 2247d5c..b55cb0b 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -54,7 +54,7 @@
 #define DFL_ALLOW_LEGACY        SSL_LEGACY_NO_RENEGOTIATION
 #define DFL_MIN_VERSION         -1
 #define DFL_MAX_VERSION         -1
-#define DFL_AUTH_MODE           SSL_VERIFY_OPTIONAL
+#define DFL_AUTH_MODE           SSL_VERIFY_REQUIRED
 
 #define GET_REQUEST "GET %s HTTP/1.0\r\n\r\n"
 
@@ -156,7 +156,7 @@
     "    max_version=%%s      default: \"\" (tls1_2)\n"     \
     "    force_version=%%s    default: \"\" (none)\n"       \
     "                        options: ssl3, tls1, tls1_1, tls1_2\n" \
-    "    auth_mode=%%s        default: \"optional\"\n"          \
+    "    auth_mode=%%s        default: \"required\"\n"      \
     "                        options: none, optional, required\n" \
     "\n"                                                    \
     "    force_ciphersuite=<name>    default: all enabled\n"\
@@ -521,7 +521,16 @@
     {
         if( ret != POLARSSL_ERR_NET_WANT_READ && ret != POLARSSL_ERR_NET_WANT_WRITE )
         {
-            printf( " failed\n  ! ssl_handshake returned -0x%x\n\n", -ret );
+            printf( " failed\n  ! ssl_handshake returned -0x%x\n", -ret );
+            if( ret == POLARSSL_ERR_X509_CERT_VERIFY_FAILED )
+                printf(
+                    "    Unable to verify the server's certificate. "
+                        "Either it is invalid,\n"
+                    "    or you didn't set ca_file or ca_path "
+                        "to an appropriate value.\n"
+                    "    Alternatively, you may want to use "
+                        "auth_mode=optional for testing purposes.\n" );
+            printf( "\n" );
             goto exit;
         }
     }
diff --git a/programs/ssl/ssl_mail_client.c b/programs/ssl/ssl_mail_client.c
index eaa44b6..4f4524a 100644
--- a/programs/ssl/ssl_mail_client.c
+++ b/programs/ssl/ssl_mail_client.c
@@ -156,6 +156,7 @@
      */
     printf( "  . Verifying peer X.509 certificate..." );
 
+    /* In real life, we may want to bail out when ret != 0 */
     if( ( ret = ssl_get_verify_result( ssl ) ) != 0 )
     {
         printf( " failed\n" );
@@ -589,6 +590,8 @@
     printf( " ok\n" );
 
     ssl_set_endpoint( &ssl, SSL_IS_CLIENT );
+    /* OPTIONAL is not optimal for security,
+     * but makes interop easier in this simplified example */
     ssl_set_authmode( &ssl, SSL_VERIFY_OPTIONAL );
 
     ssl_set_rng( &ssl, ctr_drbg_random, &ctr_drbg );