diff --git a/gramps/gen/utils/grampslocale.py b/gramps/gen/utils/grampslocale.py
index cf92e9e67..bd0620842 100644
--- a/gramps/gen/utils/grampslocale.py
+++ b/gramps/gen/utils/grampslocale.py
@@ -275,7 +275,7 @@ class GrampsLocale:
                 self.lang = loc[0]
                 self.encoding = loc[1]
             else:
-                (lang, loc) = _check_mswin_locale(locale.getdefaultlocale()[0])
+                (lang, loc) = _check_mswin_locale(locale.getlocale()[0])
                 if lang:
                     self.lang = lang
                     self.encoding = loc[1]
@@ -356,9 +356,7 @@ class GrampsLocale:
         _failure = False
         try:
             locale.setlocale(locale.LC_ALL, '')
-            if not _check_locale(locale.getdefaultlocale(envvars=('LC_ALL',
-                                                                  'LANG',
-                                                                  'LANGUAGE'))):
+            if not _check_locale(locale.getlocale(category=locale.LC_MESSAGES)):
                 LOG.debug("Usable locale not found, localization "
                           "settings ignored.")
                 self.lang = 'C'
@@ -987,22 +985,14 @@ class GrampsLocale:
         from ..lib.grampstype import GrampsType
         return GrampsType.xml_str(name)
 
-    def format(self, format, val, grouping=False, monetary=False):
-        """
-        Format a number in the current numeric locale. See python's
-        locale.format for details.  ICU's formatting codes are
-        incompatible with locale's, so just use locale.format for now.
-        """
-        return locale.format(format, val, grouping, monetary)
-
-    def format_string(self, format, val, grouping=False):
+    def format_string(self, fmt, val, grouping=False, monetary=False):
         """
         Format a string in the current numeric locale. See python's
         locale.format_string for details.  ICU's message formatting codes are
         incompatible with locale's, so just use locale.format_string
         for now.
         """
-        return locale.format_string(format, val, grouping)
+        return locale.format_string(fmt, val, grouping, monetary)
 
     def float(self, val):
         """
diff --git a/gramps/gui/widgets/histogram.py b/gramps/gui/widgets/histogram.py
index e44f57ec0..1d73d24d5 100644
--- a/gramps/gui/widgets/histogram.py
+++ b/gramps/gui/widgets/histogram.py
@@ -178,7 +178,7 @@ class Histogram(Gtk.DrawingArea):
         total = sum(self.data)
         for i in range(len(self.data)):
             if total > 0:
-                percent = glocale.format('%.2f', self.data[i] / total * 100)
+                percent = glocale.format_string('%.2f', self.data[i] / total * 100)
             else:
                 percent = ''
             layout = self.create_pango_layout(percent)
diff --git a/gramps/plugins/gramplet/pedigreegramplet.py b/gramps/plugins/gramplet/pedigreegramplet.py
index 1f11a1cef..11aec5c72 100644
--- a/gramps/plugins/gramplet/pedigreegramplet.py
+++ b/gramps/plugins/gramplet/pedigreegramplet.py
@@ -260,13 +260,13 @@ class PedigreeGramplet(Gramplet):
             if g == 0:
                 self.link(_("Generation 1"), 'PersonList', handles,
                           tooltip=_("Double-click to see people in generation"))
-                percent = glocale.format('%.2f', 100) + percent_sign
+                percent = glocale.format_string('%.2f', 100) + percent_sign
                 self.append_text(_(" has 1 of 1 individual (%(percent)s complete)\n") %  {'percent': percent})
             else:
                 all.extend(handles)
                 self.link(_("Generation %d") % g, 'PersonList', handles,
                           tooltip=_("Double-click to see people in generation %d") % g)
-                percent = glocale.format('%.2f', float(count)/2**(g-1) * 100) + percent_sign
+                percent = glocale.format_string('%.2f', float(count)/2**(g-1) * 100) + percent_sign
                 self.append_text(
                     # Translators: leave all/any {...} untranslated
                     ngettext(" has {count_person} of {max_count_person} "
diff --git a/gramps/plugins/textreport/numberofancestorsreport.py b/gramps/plugins/textreport/numberofancestorsreport.py
index a42f5fe63..15556dbd3 100644
--- a/gramps/plugins/textreport/numberofancestorsreport.py
+++ b/gramps/plugins/textreport/numberofancestorsreport.py
@@ -115,7 +115,7 @@ class NumberOfAncestorsReport(Report):
                 gen += 1
                 theoretical = math.pow(2, (gen - 1))
                 total_theoretical += theoretical
-                percent = '(%s%%)' % self._locale.format(
+                percent = '(%s%%)' % self._locale.format_string(
                     '%3.2f', ((sum(thisgen.values()) / theoretical) * 100))
 
                 # TC # English return something like: