diff --git a/MTDates/NSDate+MTDates.m b/MTDates/NSDate+MTDates.m
index ecada52..5be054d 100644
--- a/MTDates/NSDate+MTDates.m
+++ b/MTDates/NSDate+MTDates.m
@@ -111,6 +111,7 @@ + (NSDate *)mt_dateFromISOString:(NSString *)ISOString
     }
 
     NSDateFormatter* formatter = [[NSDateFormatter alloc] init];
+    [formatter setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"]];
     [formatter setCalendar:[[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian]];
     [formatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];