diff --git a/mcs/class/corlib/System/TimeZoneInfo.Unity.cs b/mcs/class/corlib/System/TimeZoneInfo.Unity.cs
index bc79e4139930..d724f464976f 100644
--- a/mcs/class/corlib/System/TimeZoneInfo.Unity.cs
+++ b/mcs/class/corlib/System/TimeZoneInfo.Unity.cs
@@ -54,6 +54,12 @@ static List<AdjustmentRule> CreateAdjustmentRule (int year, out Int64[] data, ou
 			if(daylightNameCurrentYear != names[(int)TimeZoneNames.DaylightNameIdx])
 				return rulesForYear;
 
+			// If the first and second transition DateTime objects are the same, ValidateAdjustmentRule will throw
+			// an exception. I'm unsure why these would be the same, but we do see that occur for some locales.
+			// In that case, just exit early.
+			if (firstTransition.Equals(secondTransition))
+				return rulesForYear;
+
 			var beginningOfYear = new DateTime (year, 1, 1, 0, 0, 0, 0);
 			var endOfYearDay = new DateTime (year, 12, DateTime.DaysInMonth (year, 12));
 			var endOfYearMaxTimeout = new DateTime (year, 12, DateTime.DaysInMonth(year, 12), 23, 59, 59, 999);