diff --git a/library/src/main/java/hotchemi/android/rate/AppRate.java b/library/src/main/java/hotchemi/android/rate/AppRate.java
index b9a4907..8dbdc5b 100644
--- a/library/src/main/java/hotchemi/android/rate/AppRate.java
+++ b/library/src/main/java/hotchemi/android/rate/AppRate.java
@@ -54,7 +54,7 @@ public static boolean showRateDialogIfMeetsConditions(Activity activity) {
     }
 
     private static boolean isOverDate(long targetDate, int threshold) {
-        return new Date().getTime() - targetDate >= threshold * 24 * 60 * 60 * 1000;
+        return new Date().getTime() - targetDate >= ((long)threshold) * 24 * 60 * 60 * 1000;
     }
 
     public AppRate setLaunchTimes(int launchTimes) {