diff --git a/src/main/java/APCalendar.java b/src/main/java/APCalendar.java
index cbfd206..021022a 100644
--- a/src/main/java/APCalendar.java
+++ b/src/main/java/APCalendar.java
@@ -56,6 +56,6 @@ private static int dayOfYear(int month, int day, int year)
   public static int dayOfWeek(int month, int day, int year)
   {
     /* to be implemented in part (b) */
-    return firstDayofYear(year) + dayOfYear(month, day, year) % 7;
+    return this.firstDayofYear(year) + this.dayOfYear(month, day, year) % 7;
   }
 }