diff --git a/src/main.cpp b/src/main.cpp
index ca8747de..a6c1c2fa 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2578,28 +2578,6 @@ bool CheckBlockHeader(const CBlockHeader& block, CValidationState& state, int nH
         return state.Invalid(error("CheckBlockHeader() : block timestamp too far in the future"),
                              REJECT_INVALID, "time-too-new");
 
-    CBlockIndex* pcheckpoint = Checkpoints::GetLastCheckpoint(mapBlockIndex);
-    if (pcheckpoint && block.hashPrevBlock != (chainActive.Tip() ? chainActive.Tip()->GetBlockHash() : uint256(0)))
-    {
-        // Extra checks to prevent "fill up memory by spamming with bogus blocks"
-        int64_t deltaTime = block.GetBlockTime() - pcheckpoint->nTime;
-        if (deltaTime < 0)
-        {
-			LogPrintf("CheckBlockHeader(): Height=%d, hash=%s, BlockTime=%d, Checkpoint=%d\n", nHeight, block.GetHash().GetHex().c_str(), block.GetBlockTime(), pcheckpoint->nTime);
-            return state.DoS(100, error("CheckBlockHeader() : block with timestamp before last checkpoint"),
-                             REJECT_CHECKPOINT, "time-too-old");
-        }
-        CBigNum bnNewBlock;
-        bnNewBlock.SetCompact(block.nBits);
-        CBigNum bnRequired;
-        bnRequired.SetCompact(ComputeMinWork(pcheckpoint->nBits, deltaTime));
-        if (bnNewBlock > bnRequired)
-        {
-            return state.DoS(100, error("CheckBlockHeader() : block with too little proof-of-work"),
-                             REJECT_INVALID, "bad-diffbits");
-        }
-    }
-
     return true;
 }