diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index 1050cf19e..a04e4131a 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -218,7 +218,7 @@ void CChainParams::SetCheckpointData(CChainParams::CCheckpointData checkpointDat
 int32_t MAX_BLOCK_SIZE(int32_t height)
 {
     //fprintf(stderr,"MAX_BLOCK_SIZE %d vs. %d\n",height,mainParams.consensus.vUpgrades[Consensus::UPGRADE_SAPLING].nActivationHeight);
-    if ( mainParams.consensus.vUpgrades[Consensus::UPGRADE_SAPLING].nActivationHeight > 0 && height >= mainParams.consensus.vUpgrades[Consensus::UPGRADE_SAPLING].nActivationHeight )
+    if ( height <= 0 || (mainParams.consensus.vUpgrades[Consensus::UPGRADE_SAPLING].nActivationHeight > 0 && height >= mainParams.consensus.vUpgrades[Consensus::UPGRADE_SAPLING].nActivationHeight) )
         return(4096 * 1024);
     else return(2000000);
 }