diff --git a/src/modules/calendar/e-cal-base-shell-backend.c b/src/modules/calendar/e-cal-base-shell-backend.c
index cf9171e8dd..0d64a7e9fc 100644
--- a/src/modules/calendar/e-cal-base-shell-backend.c
+++ b/src/modules/calendar/e-cal-base-shell-backend.c
@@ -23,6 +23,7 @@
 
 #include <libedataserver/libedataserver.h>
 
+#include "calendar/gui/calendar-config.h"
 #include <calendar/gui/comp-util.h>
 #include <calendar/gui/e-comp-editor.h>
 
@@ -239,6 +240,18 @@ e_cal_base_shell_backend_class_init (ECalBaseShellBackendClass *class)
 
 	/* Register relevant ESource extensions. */
 	g_type_ensure (E_TYPE_SOURCE_CALENDAR);
+
+	/* Force 24 hour format for locales which don't support 12 hour format */
+	if (!calendar_config_locale_supports_12_hour_format ()) {
+		GSettings *settings;
+
+		settings = e_util_ref_settings ("org.gnome.evolution.calendar");
+
+		if (!g_settings_get_boolean (settings, "use-24hour-format"))
+			g_settings_set_boolean (settings, "use-24hour-format", TRUE);
+
+		g_clear_object (&settings);
+	}
 }
 
 static void
diff --git a/src/modules/calendar/e-calendar-preferences.c b/src/modules/calendar/e-calendar-preferences.c
index b212fc4cf0..05ea116a13 100644
--- a/src/modules/calendar/e-calendar-preferences.c
+++ b/src/modules/calendar/e-calendar-preferences.c
@@ -717,10 +717,6 @@ calendar_preferences_construct (ECalendarPreferences *prefs,
 	locale_supports_12_hour_format =
 		calendar_config_locale_supports_12_hour_format ();
 
-	/* Force 24 hour format for locales which don't support 12 hour format */
-	if (!locale_supports_12_hour_format)
-		g_settings_set_boolean (settings, "use-24hour-format", TRUE);
-
 	/* Make sure our custom widget classes are registered with
 	 * GType before we load the GtkBuilder definition file. */
 	g_type_ensure (E_TYPE_DATE_EDIT);
@@ -835,8 +831,10 @@ calendar_preferences_construct (ECalendarPreferences *prefs,
 			widget, "use-24-hour-format",
 			G_SETTINGS_BIND_GET);
 
-	widget = e_builder_get_widget (prefs->priv->builder, "use_12_hour");
+	widget = e_builder_get_widget (prefs->priv->builder, "hbox_time_format");
 	gtk_widget_set_sensitive (widget, locale_supports_12_hour_format);
+
+	widget = e_builder_get_widget (prefs->priv->builder, "use_12_hour");
 	g_settings_bind (
 		settings, "use-24hour-format",
 		widget, "active",
@@ -844,7 +842,6 @@ calendar_preferences_construct (ECalendarPreferences *prefs,
 		G_SETTINGS_BIND_INVERT_BOOLEAN);
 
 	widget = e_builder_get_widget (prefs->priv->builder, "use_24_hour");
-	gtk_widget_set_sensitive (widget, locale_supports_12_hour_format);
 	g_settings_bind (
 		settings, "use-24hour-format",
 		widget, "active",