diff --git a/PoW.py b/PoW.py
index deb573d..1b29ed7 100644
--- a/PoW.py
+++ b/PoW.py
@@ -2,7 +2,7 @@ import hashlib
 
 def check(data, proof, complexity=1, f=hashlib.sha256):
     zeros="0"*complexity
-    hash=f(data+proof)
+    hash=f(proof+data)
     hashdata=hash.hexdigest()
     b=0
     for a in hashdata: