diff --git a/core/tests/coretests/src/android/text/format/DateUtilsTest.java b/core/tests/coretests/src/android/text/format/DateUtilsTest.java
index f8e3b4dfec56f..872b71a5faa6d 100644
--- a/core/tests/coretests/src/android/text/format/DateUtilsTest.java
+++ b/core/tests/coretests/src/android/text/format/DateUtilsTest.java
@@ -117,7 +117,7 @@ public class DateUtilsTest {
     @Test
     public void testFormatSameDayTime() {
         // This test assumes a default DateFormat.is24Hour setting.
-        DateFormat.is24Hour = null;
+        DateFormat.set24HourTimePref(null);
         Date date = new Date(109, 0, 19, 3, 30, 15);
         long fixedTime = date.getTime();