diff --git a/luaj-core/src/main/java/org/luaj/vm2/lib/MathLib.java b/luaj-core/src/main/java/org/luaj/vm2/lib/MathLib.java
index 291b3fb5..ea2f6af0 100644
--- a/luaj-core/src/main/java/org/luaj/vm2/lib/MathLib.java
+++ b/luaj-core/src/main/java/org/luaj/vm2/lib/MathLib.java
@@ -300,7 +300,7 @@ public class MathLib extends TwoArgFunction {
 			LuaValue n = args.arg1();
 			/* number is its own integer part, no fractional part */
 			if (n.islong())
-				return varargsOf(n, valueOf(0.0));
+				return varargsOf(n.tonumber(), valueOf(0.0));
 			double x = n.checkdouble();
 			/* integer part (rounds toward zero) */
 			double intPart = x > 0? Math.floor(x): Math.ceil(x);