diff --git a/tests/python/ipnbdoctest.py b/tests/python/ipnbdoctest.py
index 6a3005370..9b8ed95ee 100755
--- a/tests/python/ipnbdoctest.py
+++ b/tests/python/ipnbdoctest.py
@@ -285,7 +285,7 @@ def test_notebook(ipynb):
             print("output length mismatch (expected {}, got {})".format(
                   len(cell.outputs), len(outs)))
             failed = True
-        if not compare_outputs(outs, cell.outputs):
+        if not compare_outputs(cell.outputs, outs):
             failed = True
         print("cell %d: " % i, end="")
         if failed:
diff --git a/tests/run.in b/tests/run.in
index 77263f8f9..ecfff458a 100755
--- a/tests/run.in
+++ b/tests/run.in
@@ -1,7 +1,7 @@
 #!/bin/sh
 # -*- coding: utf-8 -*-
-# Copyright (C) 2010, 2011, 2014, 2015, 2016 Laboratoire de Recherche et
-# Developpement de l'EPITA (LRDE).
+# Copyright (C) 2010, 2011, 2014-2016, 2018 Laboratoire de Recherche
+# et Developpement de l'EPITA (LRDE).
 # Copyright (C) 2003, 2004 Laboratoire d'Informatique de Paris 6
 # (LIP6), département Systèmes Répartis Coopératifs (SRC), Université
 # Pierre et Marie Curie.
@@ -92,6 +92,7 @@ export srcdir
 case $1 in
   *.ipynb)
     PYTHONPATH=$pypath DYLD_LIBRARY_PATH=$modpath \
+    PYTHONIOENCODING=utf-8:surrogateescape \
     exec $PREFIXCMD @PYTHON@ @abs_srcdir@/python/ipnbdoctest.py "$@";;
   *.py)
     PYTHONPATH=$pypath DYLD_LIBRARY_PATH=$modpath \