diff --git a/latex/latex.py b/latex/latex.py
index 0034e38..dcf2aae 100644
--- a/latex/latex.py
+++ b/latex/latex.py
@@ -161,8 +161,8 @@ class LatexRenderer(Thread):
         except Exception:
             msg = 'Could not create temporary files for Latex plugin'
             log.debug(msg)
-            self.show_error(_('latex error: %s\n===ORIGINAL CODE====\n%s') % (
-                msg, self.code[2:len(self.code)-2]))
+            self.show_error(_('latex error: %(error)s\n===ORIGINAL CODE====\n'
+            '%(code)s') % {'error': msg, 'code': self.code[2:len(self.code)-2]})
             return False
 
         tmpfile = os.path.join(tmpdir, 'gajim_tex')
diff --git a/regex_filter/regex_filter.py b/regex_filter/regex_filter.py
index e86aa04..6c53f6c 100644
--- a/regex_filter/regex_filter.py
+++ b/regex_filter/regex_filter.py
@@ -111,7 +111,8 @@ class FilterCommands(CommandContainer):
     def add_filter(self, search, replace):
         plugin = app.plugin_manager.get_active_plugin('regex_filter')
         plugin.add_rule(search, replace)
-        return _('Added rule to replace %s by %s' % (search, replace))
+        return _('Added rule to replace %(search)s by %(replace)s' % {
+            'search': search, 'replace': replace})
 
     @command("remove_filter", raw=True)
     @doc(_("Remove an incoming filter. Argument is the rule number. "