diff --git a/src/test/java/org/json/junit/data/CustomClassJ.java b/src/test/java/org/json/junit/data/CustomClassJ.java
index 79e4ca4..62cce3e 100644
--- a/src/test/java/org/json/junit/data/CustomClassJ.java
+++ b/src/test/java/org/json/junit/data/CustomClassJ.java
@@ -4,5 +4,7 @@ public class CustomClassJ {
   public static String classState = "original";
   public int number;
 
-  public CustomClassJ() {}
+  public CustomClassJ() {
+    // Required for JSONObject#fromJson(Class<T>) tests.
+  }
 }