diff --git a/library/src/main/java/com/alamkanak/weekview/WeekView.java b/library/src/main/java/com/alamkanak/weekview/WeekView.java
index b18a544b5..6fb019112 100755
--- a/library/src/main/java/com/alamkanak/weekview/WeekView.java
+++ b/library/src/main/java/com/alamkanak/weekview/WeekView.java
@@ -1481,7 +1481,7 @@ private boolean isEventsCollide(WeekViewEvent event1, WeekViewEvent event2) {
         long start2 = event2.getStartTime().getTimeInMillis();
         long end2 = event2.getEndTime().getTimeInMillis();
 
-        long minOverlappingMillis = mMinOverlappingMinutes * 60 * 1000;
+        long minOverlappingMillis = mMinOverlappingMinutes * 60L * 1000L;
 
         return !((start1 + minOverlappingMillis >= end2) || (end1 <= start2 + minOverlappingMillis));
     }