diff --git a/AlgebraicDataflowArchitectureModel/src/code/ast/NumberLiteral.java b/AlgebraicDataflowArchitectureModel/src/code/ast/NumberLiteral.java
index c397e24..952450c 100644
--- a/AlgebraicDataflowArchitectureModel/src/code/ast/NumberLiteral.java
+++ b/AlgebraicDataflowArchitectureModel/src/code/ast/NumberLiteral.java
@@ -53,6 +53,8 @@
 		
 		if (NumberUtil.isHexNumber(tokenValue)) {
 			this.tokenValue = tokenValue;
+		} else {
+			throw new IllegalArgumentException("Invalid number literal: " + tokenValue);
 		}
 	}