diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index aeec331..9d64d2a 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -1587,8 +1587,8 @@
 
         if( ret != 0 )
         {
-            mbedtls_printf( " failed\n  ! mbedtls_ssl_conf_cid_len returned %d\n\n",
-                            ret );
+            mbedtls_printf( " failed\n  ! mbedtls_ssl_conf_cid_len returned -%#04x\n\n",
+                            -ret );
             goto exit;
         }
     }
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index ced8086..59e40e0 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -2407,8 +2407,8 @@
 
         if( ret != 0 )
         {
-            mbedtls_printf( " failed\n  ! mbedtls_ssl_conf_cid_len returned %d\n\n",
-                            ret );
+            mbedtls_printf( " failed\n  ! mbedtls_ssl_conf_cid_len returned -%#04x\n\n",
+                            -ret );
             goto exit;
         }
     }