diff --git a/core/types/block.go b/core/types/block.go
index de4ed128506a..071666a801fa 100644
--- a/core/types/block.go
+++ b/core/types/block.go
@@ -154,25 +154,6 @@ func (h *Header) Size() common.StorageSize {
 	return common.StorageSize(unsafe.Sizeof(*h)) + common.StorageSize(len(h.Extra)+(h.Difficulty.BitLen()+h.Number.BitLen()+h.Time.BitLen())/8)
 }
 
-// SanityCheck checks a few basic things -- these checks are way beyond what
-// any 'sane' production values should hold, and can mainly be used to prevent
-// that the unbounded fields are stuffed with junk data to add processing
-// overhead
-func (h *Header) SanityCheck() error {
-	if h.Number != nil && !h.Number.IsUint64() {
-		return fmt.Errorf("too large block number: bitlen %d", h.Number.BitLen())
-	}
-	if h.Difficulty != nil {
-		if diffLen := h.Difficulty.BitLen(); diffLen > 80 {
-			return fmt.Errorf("too large block difficulty: bitlen %d", diffLen)
-		}
-	}
-	if eLen := len(h.Extra); eLen > 100*1024 {
-		return fmt.Errorf("too large block extradata: size %d", eLen)
-	}
-	return nil
-}
-
 // Body is a simple (mutable, non-safe) data container for storing and moving
 // a block's data contents (transactions and uncles) together.
 type Body struct {
@@ -388,12 +369,6 @@ func (b *Block) Size() common.StorageSize {
 	return common.StorageSize(c)
 }
 
-// SanityCheck can be used to prevent that unbounded fields are
-// stuffed with junk data to add processing overhead
-func (b *Block) SanityCheck() error {
-	return b.header.SanityCheck()
-}
-
 type writeCounter common.StorageSize
 
 func (c *writeCounter) Write(b []byte) (int, error) {
diff --git a/eth/fetcher/block_fetcher.go b/eth/fetcher/block_fetcher.go
index 856c5cfd06e7..642ce6e48fb5 100644
--- a/eth/fetcher/block_fetcher.go
+++ b/eth/fetcher/block_fetcher.go
@@ -804,7 +804,7 @@ func (f *BlockFetcher) forgetHash(hash common.Hash) {
 	// Remove all pending announces and decrement DOS counters
 	for _, announce := range f.announced[hash] {
 		f.announces[announce.origin]--
-		if f.announces[announce.origin] <= 0 {
+		if f.announces[announce.origin] == 0 {
 			delete(f.announces, announce.origin)
 		}
 	}
@@ -815,7 +815,7 @@ func (f *BlockFetcher) forgetHash(hash common.Hash) {
 	// Remove any pending fetches and decrement the DOS counters
 	if announce := f.fetching[hash]; announce != nil {
 		f.announces[announce.origin]--
-		if f.announces[announce.origin] <= 0 {
+		if f.announces[announce.origin] == 0 {
 			delete(f.announces, announce.origin)
 		}
 		delete(f.fetching, hash)
@@ -824,7 +824,7 @@ func (f *BlockFetcher) forgetHash(hash common.Hash) {
 	// Remove any pending completion requests and decrement the DOS counters
 	for _, announce := range f.fetched[hash] {
 		f.announces[announce.origin]--
-		if f.announces[announce.origin] <= 0 {
+		if f.announces[announce.origin] == 0 {
 			delete(f.announces, announce.origin)
 		}
 	}
@@ -833,7 +833,7 @@ func (f *BlockFetcher) forgetHash(hash common.Hash) {
 	// Remove any pending completions and decrement the DOS counters
 	if announce := f.completing[hash]; announce != nil {
 		f.announces[announce.origin]--
-		if f.announces[announce.origin] <= 0 {
+		if f.announces[announce.origin] == 0 {
 			delete(f.announces, announce.origin)
 		}
 		delete(f.completing, hash)
diff --git a/eth/handler.go b/eth/handler.go
index b2f0b39a9cd4..786a28fb7e26 100644
--- a/eth/handler.go
+++ b/eth/handler.go
@@ -810,9 +810,6 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 		if err := msg.Decode(&request); err != nil {
 			return errResp(ErrDecode, "%v: %v", msg, err)
 		}
-		if err := request.sanityCheck(); err != nil {
-			return err
-		}
 		request.Block.ReceivedAt = msg.ReceivedAt
 		request.Block.ReceivedFrom = p
 
diff --git a/eth/protocol.go b/eth/protocol.go
index d037d6afe11a..819db3c857a9 100644
--- a/eth/protocol.go
+++ b/eth/protocol.go
@@ -233,19 +233,6 @@ type newBlockData struct {
 	TD    *big.Int
 }
 
-// sanityCheck verifies that the values are reasonable, as a DoS protection
-func (request *newBlockData) sanityCheck() error {
-	if err := request.Block.SanityCheck(); err != nil {
-		return err
-	}
-	//TD at mainnet block #7753254 is 76 bits. If it becomes 100 million times
-	// larger, it will still fit within 100 bits
-	if tdlen := request.TD.BitLen(); tdlen > 100 {
-		return fmt.Errorf("too large block TD: bitlen %d", tdlen)
-	}
-	return nil
-}
-
 // blockBody represents the data content of a single block.
 type blockBody struct {
 	Transactions []*types.Transaction // Transactions contained within a block
diff --git a/les/handler.go b/les/handler.go
index d7c3e84302be..37cb0b4290c7 100644
--- a/les/handler.go
+++ b/les/handler.go
@@ -385,9 +385,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 		if err := msg.Decode(&req); err != nil {
 			return errResp(ErrDecode, "%v: %v", msg, err)
 		}
-		if err := req.sanityCheck(); err != nil {
-			return err
-		}
+
 		if p.requestAnnounceType == announceTypeSigned {
 			if err := req.checkSignature(p.ID()); err != nil {
 				p.Log().Trace("Invalid announcement signature", "err", err)
diff --git a/les/protocol.go b/les/protocol.go
index c3ef953051fc..036064ec21eb 100644
--- a/les/protocol.go
+++ b/les/protocol.go
@@ -137,14 +137,6 @@ type announceData struct {
 	Update     keyValueList
 }
 
-// sanityCheck verifies that the values are reasonable, as a DoS protection
-func (a *announceData) sanityCheck() error {
-	if tdlen := a.Td.BitLen(); tdlen > 100 {
-		return fmt.Errorf("too large block TD: bitlen %d", tdlen)
-	}
-	return nil
-}
-
 // sign adds a signature to the block announcement by the given privKey
 func (a *announceData) sign(privKey *ecdsa.PrivateKey) {
 	rlp, _ := rlp.EncodeToBytes(announceBlock{a.Hash, a.Number, a.Td})