diff --git a/src/core/org/luaj/vm2/lib/StringLib.java b/src/core/org/luaj/vm2/lib/StringLib.java
index 98d4c3b4..513f77ea 100644
--- a/src/core/org/luaj/vm2/lib/StringLib.java
+++ b/src/core/org/luaj/vm2/lib/StringLib.java
@@ -173,7 +173,7 @@ public class StringLib extends TwoArgFunction {
 	 * TODO: port dumping code as optional add-on
 	 */
 	static final class dump extends VarArgFunction {
-		public LuaValue invoke(Varargs args) {
+		public Varargs invoke(Varargs args) {
 			LuaValue f = args.checkfunction(1);
 			ByteArrayOutputStream baos = new ByteArrayOutputStream();
 			try {