diff --git a/tests/hamming/src/main/java/Hamming.java b/tests/hamming/src/main/java/Hamming.java
index cce71fbe..7890e831 100644
--- a/tests/hamming/src/main/java/Hamming.java
+++ b/tests/hamming/src/main/java/Hamming.java
@@ -12,16 +12,9 @@ class Hamming {
 
     
     private void validate(String leftStrand, String rightStrand) {
-    	validateNotNull(leftStrand, rightStrand);
     	validateSameLength(leftStrand, rightStrand);
     }
 
-	private void validateNotNull(String leftStrand, String rightStrand) {
-		if (leftStrand == null || rightStrand == null) {
-			throw new IllegalArgumentException("Either left or right stand is null");
-		}
-	}
-
 	private void validateSameLength(String leftStrand, String rightStrand) {
 		if (leftStrand.length() != rightStrand.length()) {
 			throw new IllegalArgumentException("leftStrand and rightStrand must be of equal length.");