diff --git a/nx01-x4o-fc18/src/main/java/org/x4o/fc18/FourCornerRecipe.java b/nx01-x4o-fc18/src/main/java/org/x4o/fc18/FourCornerRecipe.java
index f126815..54d7484 100644
--- a/nx01-x4o-fc18/src/main/java/org/x4o/fc18/FourCornerRecipe.java
+++ b/nx01-x4o-fc18/src/main/java/org/x4o/fc18/FourCornerRecipe.java
@@ -134,7 +134,7 @@ final public class FourCornerRecipe {
 	}
 	
 	static final private BigInteger NCR1632_MASK_PAGE = BigInteger.valueOf(0x1FF);
-	static final private BigInteger NCR1632_MASK_MAX = new BigInteger("FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF", 16);
+	static final private BigInteger NCR1632_VALUE_MAX = new BigInteger("FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF"+"FFFFFFFFFFFFFFFFFF", 16);
 	
 	static private List<Integer> embedNCR1632Value(List<Integer> result, BigInteger value, int bankStart) {
 		if (value.equals(BigInteger.ZERO)) {
@@ -143,7 +143,7 @@ final public class FourCornerRecipe {
 		//if (value.signum() == -1) {
 		//	// TODO: check if we need one octal for pos/neg/qNaN/sNaN/pos_inf/neg_inf/free/free options
 		//}
-		if (value.and(NCR1632_MASK_MAX).equals(BigInteger.ZERO)) {
+		if (value.compareTo(NCR1632_VALUE_MAX) > 0) {
 			throw new IllegalArgumentException("Value is larger than 576 bit: " + value);
 		}
 		BigInteger valueZero = value.subtract(BigInteger.ONE);