diff --git a/les/handler.go b/les/handler.go
index 1102a0f0cb..619eaf3221 100644
--- a/les/handler.go
+++ b/les/handler.go
@@ -528,7 +528,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 						origin = pm.blockchain.GetHeaderByNumber(query.Origin.Number)
 					}
 					if origin == nil {
-						atomic.AddUint64(&p.invalidReq, 1)
+						atomic.AddUint32(&p.invalidReq, 1)
 						break
 					}
 					headers = append(headers, origin)
@@ -638,7 +638,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 					}
 					number := rawdb.ReadHeaderNumber(pm.chainDb, hash)
 					if number == nil {
-						atomic.AddUint64(&p.invalidReq, 1)
+						atomic.AddUint32(&p.invalidReq, 1)
 						continue
 					}
 					if data := rawdb.ReadBodyRLP(pm.chainDb, hash, *number); len(data) != 0 {
@@ -698,7 +698,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 					number := rawdb.ReadHeaderNumber(pm.chainDb, request.BHash)
 					if number == nil {
 						p.Log().Warn("Failed to retrieve block num for code", "hash", request.BHash)
-						atomic.AddUint64(&p.invalidReq, 1)
+						atomic.AddUint32(&p.invalidReq, 1)
 						continue
 					}
 					header := rawdb.ReadHeader(pm.chainDb, request.BHash, *number)
@@ -711,7 +711,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 					local := pm.blockchain.CurrentHeader().Number.Uint64()
 					if !pm.server.archiveMode && header.Number.Uint64()+core.TriesInMemory <= local {
 						p.Log().Debug("Reject stale code request", "number", header.Number.Uint64(), "head", local)
-						atomic.AddUint64(&p.invalidReq, 1)
+						atomic.AddUint32(&p.invalidReq, 1)
 						continue
 					}
 					triedb := pm.blockchain.StateCache().TrieDB()
@@ -719,7 +719,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 					account, err := pm.getAccount(triedb, header.Root, common.BytesToHash(request.AccKey))
 					if err != nil {
 						p.Log().Warn("Failed to retrieve account for code", "block", header.Number, "hash", header.Hash(), "account", common.BytesToHash(request.AccKey), "err", err)
-						atomic.AddUint64(&p.invalidReq, 1)
+						atomic.AddUint32(&p.invalidReq, 1)
 						continue
 					}
 					code, err := triedb.Node(common.BytesToHash(account.CodeHash))
@@ -788,7 +788,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 					var results types.Receipts
 					number := rawdb.ReadHeaderNumber(pm.chainDb, hash)
 					if number == nil {
-						atomic.AddUint64(&p.invalidReq, 1)
+						atomic.AddUint32(&p.invalidReq, 1)
 						continue
 					}
 					results = rawdb.ReadRawReceipts(pm.chainDb, hash, *number)
@@ -866,7 +866,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 
 						if number = rawdb.ReadHeaderNumber(pm.chainDb, request.BHash); number == nil {
 							p.Log().Warn("Failed to retrieve block num for proof", "hash", request.BHash)
-							atomic.AddUint64(&p.invalidReq, 1)
+							atomic.AddUint32(&p.invalidReq, 1)
 							continue
 						}
 						if header = rawdb.ReadHeader(pm.chainDb, request.BHash, *number); header == nil {
@@ -878,7 +878,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 						local := pm.blockchain.CurrentHeader().Number.Uint64()
 						if !pm.server.archiveMode && header.Number.Uint64()+core.TriesInMemory <= local {
 							p.Log().Debug("Reject stale trie request", "number", header.Number.Uint64(), "head", local)
-							atomic.AddUint64(&p.invalidReq, 1)
+							atomic.AddUint32(&p.invalidReq, 1)
 							continue
 						}
 						root = header.Root
@@ -903,7 +903,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 						account, err := pm.getAccount(statedb.TrieDB(), root, common.BytesToHash(request.AccKey))
 						if err != nil {
 							p.Log().Warn("Failed to retrieve account for proof", "block", header.Number, "hash", header.Hash(), "account", common.BytesToHash(request.AccKey), "err", err)
-							atomic.AddUint64(&p.invalidReq, 1)
+							atomic.AddUint32(&p.invalidReq, 1)
 							continue
 						}
 						trie, err = statedb.OpenStorageTrie(common.BytesToHash(request.AccKey), account.Root)
@@ -1152,7 +1152,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 	}
 	// If the client has made too much invalid request(e.g. request a non-exist data),
 	// reject them to prevent SPAM attack.
-	if atomic.LoadUint64(&p.invalidReq) > maxRequestErrors {
+	if atomic.LoadUint32(&p.invalidReq) > maxRequestErrors {
 		return errTooManyInvalidRequest
 	}
 	return nil
diff --git a/les/peer.go b/les/peer.go
index 5c678cb7e9..67fbde66d4 100644
--- a/les/peer.go
+++ b/les/peer.go
@@ -71,11 +71,6 @@ const (
 )
 
 type peer struct {
-	// WARNING: The `invalidReq` field is accessed atomically. On 32 bit platforms, only
-	// 64-bit aligned fields can be atomic. The struct is guaranteed to be so aligned,
-	// so take advantage of that (https://golang.org/pkg/sync/atomic/#pkg-note-BUG).
-	invalidReq uint64
-
 	*p2p.Peer
 	rw p2p.MsgReadWriter
 
@@ -96,6 +91,7 @@ type peer struct {
 	// RequestProcessed is called
 	responseLock  sync.Mutex
 	responseCount uint64
+	invalidReq    uint32
 
 	poolEntry      *poolEntry
 	hasBlock       func(common.Hash, uint64, bool) bool