diff --git a/app/src/main/java/protect/card_locker/DBHelper.java b/app/src/main/java/protect/card_locker/DBHelper.java
index fa670894e..56b2c4a71 100644
--- a/app/src/main/java/protect/card_locker/DBHelper.java
+++ b/app/src/main/java/protect/card_locker/DBHelper.java
@@ -24,6 +24,8 @@ public class DBHelper extends SQLiteOpenHelper {
     public static final String DATABASE_NAME = "Catima.db";
     public static final int ORIGINAL_DATABASE_VERSION = 1;
     public static final int DATABASE_VERSION = 16;
+
+    // NB: changing this value requires a migration
     public static final int DEFAULT_ZOOM_LEVEL = 100;
 
     public static class LoyaltyCardDbGroups {