diff --git a/src/cc/sudoku.cpp b/src/cc/sudoku.cpp
index 6a0f97583..4f8702c0a 100644
--- a/src/cc/sudoku.cpp
+++ b/src/cc/sudoku.cpp
@@ -2944,7 +2944,7 @@ UniValue sudoku_solution(uint64_t txfee,struct CCcontract_info *cp,cJSON *params
 
 bool sudoku_validate(struct CCcontract_info *cp,int32_t height,Eval *eval,const CTransaction tx)
 {
-    CScript scriptPubKey; std::vector<uint8_t> vopret; uint8_t *script,e,f,funcid; int32_t score,numvouts; char unsolved[82],solution[82]; uint32_t timestamps[81];
+    CScript scriptPubKey; std::vector<uint8_t> vopret; uint8_t *script,e,f,funcid; int32_t i,score,numvouts; char unsolved[82],solution[82]; uint32_t timestamps[81];
     if ( (numvouts= tx.vout.size()) > 1 )
     {
         scriptPubKey = tx.vout[numvouts-1].scriptPubKey;