diff --git a/glib/gdatetime.c b/glib/gdatetime.c
index 429cadefc..142338128 100644
--- a/glib/gdatetime.c
+++ b/glib/gdatetime.c
@@ -622,7 +622,7 @@ g_date_time_get_week_number (GDateTime *datetime,
                              gint      *day_of_week,
                              gint      *day_of_year)
 {
-  gint a, b, c, d, e, f, g, n, s, month, day, year;
+  gint a, b, c, d, e, f, g, n, s, month = -1, day = -1, year = -1;
 
   g_date_time_get_ymd (datetime, &year, &month, &day);
 
@@ -2342,7 +2342,7 @@ g_date_time_get_day_of_month (GDateTime *datetime)
 gint
 g_date_time_get_week_numbering_year (GDateTime *datetime)
 {
-  gint year, month, day, weekday;
+  gint year = -1, month = -1, day = -1, weekday;
 
   g_date_time_get_ymd (datetime, &year, &month, &day);
   weekday = g_date_time_get_day_of_week (datetime);