--- a/cubicweb/ext/rest.py	Thu Jun 28 11:19:14 2018 +0200
+++ b/cubicweb/ext/rest.py	Thu Jun 28 12:19:16 2018 +0200
@@ -404,7 +404,7 @@
     """
     req = context._cw
     if isinstance(data, text_type):
-        encoding = 'unicode'
+        encoding = 'utf-8'
         # remove unprintable characters unauthorized in xml
         data = data.translate(ESC_UCAR_TABLE)
     else: