diff --git a/lib/local_comms.js b/lib/local_comms.js
index 0e8335e4..fbfa473a 100644
--- a/lib/local_comms.js
+++ b/lib/local_comms.js
@@ -470,7 +470,7 @@ function Database(){
 
     this.lockBlock = function(blockId){
         let txn = this.env.beginTxn();
-        let blockProto = txn.getBinary(this.blockDB, blockId);
+        let blockProto = txn.getBinary(this.blockDB, parseInt(blockId));
         if (blockProto !== null){
             let blockData = global.protos.Block.decode(blockProto);
             blockData.unlocked = false;