diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index bf84989..cc5c02e 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -195,10 +195,10 @@ public:
 
         
         // The best chain should have at least this much work.
-        consensus.nMinimumChainWork = uint256S("0x00");
+        consensus.nMinimumChainWork = uint256S("0x00000000000000000000000000000000000000000000000000003077e5d4c957"); // Current testnet chainwork
 
         // By default assume that the signatures in ancestors of this block are valid.
-        consensus.defaultAssumeValid = uint256S("0x00");
+        consensus.defaultAssumeValid = uint256S("0x0000000000f8470a0cc0f6210b23bbeba248bf937205e34588aa84596b72c3bd"); // Current best block hash
 
 
         consensus.powLimit = uint256S("00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 5277d63..e1a5a6d 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -491,10 +491,10 @@ static UniValue getblocktemplate(const JSONRPCRequest& request)
     if (g_rpc_node->connman->GetNodeCount(CConnman::CONNECTIONS_ALL) == 0)
         throw JSONRPCError(RPC_CLIENT_NOT_CONNECTED, PACKAGE_NAME " is not connected!");
 
-    // PATCH: Allow getblocktemplate even during initial block download for testnet purposes
-    // TODO: Remove this patch for mainnet - it's only for testnet startup
-    // if (::ChainstateActive().IsInitialBlockDownload())
-    //     throw JSONRPCError(RPC_CLIENT_IN_INITIAL_DOWNLOAD, PACKAGE_NAME " is in initial sync and waiting for blocks...");
+    // Block getblocktemplate during initial block download for security
+    if (::ChainstateActive().IsInitialBlockDownload()) {
+        throw JSONRPCError(RPC_CLIENT_IN_INITIAL_DOWNLOAD, PACKAGE_NAME " is in initial sync and waiting for blocks...");
+    }
 
     static unsigned int nTransactionsUpdatedLast;
     const CTxMemPool& mempool = EnsureMemPool();