diff --git a/lnwallet/channel.go b/lnwallet/channel.go
index 379ccbb7..f654d1c6 100644
--- a/lnwallet/channel.go
+++ b/lnwallet/channel.go
@@ -4433,6 +4433,22 @@ func (lc *LightningChannel) LoadFwdPkgs() ([]*channeldb.FwdPkg, error) {
 	return lc.channelState.LoadFwdPkgs()
 }
 
+// AckAddHtlcs sets a bit in the FwdFilter of a forwarding package belonging to
+// this channel, that corresponds to the given AddRef. This method also succeeds
+// if no forwarding package is found.
+func (lc *LightningChannel) AckAddHtlcs(addRef channeldb.AddRef) error {
+	return lc.channelState.AckAddHtlcs(addRef)
+}
+
+// AckSettleFails sets a bit in the SettleFailFilter of a forwarding package
+// belonging to this channel, that corresponds to the given SettleFailRef. This
+// method also succeeds if no forwarding package is found.
+func (lc *LightningChannel) AckSettleFails(
+	settleFailRefs ...channeldb.SettleFailRef) error {
+
+	return lc.channelState.AckSettleFails(settleFailRefs...)
+}
+
 // SetFwdFilter writes the forwarding decision for a given remote commitment
 // height.
 func (lc *LightningChannel) SetFwdFilter(height uint64,
@@ -4572,21 +4588,18 @@ func (lc *LightningChannel) SettleHTLC(preimage [32]byte,
 
 	htlc := lc.remoteUpdateLog.lookupHtlc(htlcIndex)
 	if htlc == nil {
-		return fmt.Errorf("No HTLC with ID %d in channel %v", htlcIndex,
-			lc.ShortChanID())
+		return ErrUnknownHtlcIndex{lc.ShortChanID(), htlcIndex}
 	}
 
 	// Now that we know the HTLC exists, before checking to see if the
 	// preimage matches, we'll ensure that we haven't already attempted to
 	// modify the HTLC.
 	if lc.remoteUpdateLog.htlcHasModification(htlcIndex) {
-		return fmt.Errorf("HTLC with ID %d has already been settled",
-			htlcIndex)
+		return ErrHtlcIndexAlreadySettled(htlcIndex)
 	}
 
 	if htlc.RHash != sha256.Sum256(preimage[:]) {
-		return fmt.Errorf("Invalid payment preimage %x for hash %x",
-			preimage[:], htlc.RHash[:])
+		return ErrInvalidSettlePreimage{preimage[:], htlc.RHash[:]}
 	}
 
 	pd := &PaymentDescriptor{
@@ -4620,21 +4633,18 @@ func (lc *LightningChannel) ReceiveHTLCSettle(preimage [32]byte, htlcIndex uint6
 
 	htlc := lc.localUpdateLog.lookupHtlc(htlcIndex)
 	if htlc == nil {
-		return fmt.Errorf("No HTLC with ID %d in channel %v", htlcIndex,
-			lc.ShortChanID())
+		return ErrUnknownHtlcIndex{lc.ShortChanID(), htlcIndex}
 	}
 
 	// Now that we know the HTLC exists, before checking to see if the
 	// preimage matches, we'll ensure that they haven't already attempted
 	// to modify the HTLC.
 	if lc.localUpdateLog.htlcHasModification(htlcIndex) {
-		return fmt.Errorf("HTLC with ID %d has already been settled",
-			htlcIndex)
+		return ErrHtlcIndexAlreadySettled(htlcIndex)
 	}
 
 	if htlc.RHash != sha256.Sum256(preimage[:]) {
-		return fmt.Errorf("Invalid payment preimage %x for hash %x",
-			preimage[:], htlc.RHash[:])
+		return ErrInvalidSettlePreimage{preimage[:], htlc.RHash[:]}
 	}
 
 	pd := &PaymentDescriptor{
@@ -4688,15 +4698,13 @@ func (lc *LightningChannel) FailHTLC(htlcIndex uint64, reason []byte,
 
 	htlc := lc.remoteUpdateLog.lookupHtlc(htlcIndex)
 	if htlc == nil {
-		return fmt.Errorf("No HTLC with ID %d in channel %v", htlcIndex,
-			lc.ShortChanID())
+		return ErrUnknownHtlcIndex{lc.ShortChanID(), htlcIndex}
 	}
 
 	// Now that we know the HTLC exists, we'll ensure that we haven't
 	// already attempted to fail the HTLC.
 	if lc.remoteUpdateLog.htlcHasModification(htlcIndex) {
-		return fmt.Errorf("HTLC with ID %d has already been failed",
-			htlcIndex)
+		return ErrHtlcIndexAlreadyFailed(htlcIndex)
 	}
 
 	pd := &PaymentDescriptor{
@@ -4740,15 +4748,13 @@ func (lc *LightningChannel) MalformedFailHTLC(htlcIndex uint64,
 
 	htlc := lc.remoteUpdateLog.lookupHtlc(htlcIndex)
 	if htlc == nil {
-		return fmt.Errorf("No HTLC with ID %d in channel %v", htlcIndex,
-			lc.ShortChanID())
+		return ErrUnknownHtlcIndex{lc.ShortChanID(), htlcIndex}
 	}
 
 	// Now that we know the HTLC exists, we'll ensure that we haven't
 	// already attempted to fail the HTLC.
 	if lc.remoteUpdateLog.htlcHasModification(htlcIndex) {
-		return fmt.Errorf("HTLC with ID %d has already been failed",
-			htlcIndex)
+		return ErrHtlcIndexAlreadyFailed(htlcIndex)
 	}
 
 	pd := &PaymentDescriptor{
@@ -4785,15 +4791,13 @@ func (lc *LightningChannel) ReceiveFailHTLC(htlcIndex uint64, reason []byte,
 
 	htlc := lc.localUpdateLog.lookupHtlc(htlcIndex)
 	if htlc == nil {
-		return fmt.Errorf("No HTLC with ID %d in channel %v", htlcIndex,
-			lc.ShortChanID())
+		return ErrUnknownHtlcIndex{lc.ShortChanID(), htlcIndex}
 	}
 
 	// Now that we know the HTLC exists, we'll ensure that they haven't
 	// already attempted to fail the HTLC.
 	if lc.localUpdateLog.htlcHasModification(htlcIndex) {
-		return fmt.Errorf("HTLC with ID %d has already been failed",
-			htlcIndex)
+		return ErrHtlcIndexAlreadyFailed(htlcIndex)
 	}
 
 	pd := &PaymentDescriptor{