diff --git a/src/main.cpp b/src/main.cpp
index c5a548072..76f20cbb0 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1607,7 +1607,7 @@ bool myGetTransaction(const uint256 &hash, CTransaction &txOut, uint256 &hashBlo
 {
     // need a GetTransaction without lock so the validation code for assets can run without deadlock
     {
-        READLOCK(mempool.cs);
+        LOCK(mempool.cs);
         fprintf(stderr,"check mempool\n");
         if (mempool.lookup(hash, txOut))
         {