diff --git a/src/main/java/cokr/xit/foundation/data/DataObject.java b/src/main/java/cokr/xit/foundation/data/DataObject.java
index cfab17a..3048417 100644
--- a/src/main/java/cokr/xit/foundation/data/DataObject.java
+++ b/src/main/java/cokr/xit/foundation/data/DataObject.java
@@ -1,8 +1,8 @@
 package cokr.xit.foundation.data;
 
 import java.util.Map;
-import java.util.function.Function;
 import java.util.function.Supplier;
+import java.util.function.UnaryOperator;
 
 import cokr.xit.foundation.Assert;
 
@@ -120,7 +120,7 @@ public class DataObject extends StringMap<Object> {
 		return bool.booleanValue();
 	}
 
-	public DataObject convert(String name, Function<Object, ?> converter) {
+	public DataObject convert(String name, UnaryOperator<Object> converter) {
 		Object obj = get(name);
 		return set(name, converter.apply(obj));
 	}