diff --git a/BEP131.md b/BEP131.md
index 9024ee54..c39b5712 100644
--- a/BEP131.md
+++ b/BEP131.md
@@ -75,7 +75,7 @@ Function Select(cabinet, candidate, M)
 Function Shuffle(validators, limit)
     n = len(validators)
     for i <- 0 to limit-1
-        idx = keccak256(epochNumber+validators[i].consensusAddr) mod n
+        idx = keccak256(epochNumber, i) mod n
         // Do swap 
         validators[i], validators[idx] = validators[idx], validators[i]
 ```