diff --git a/lnwallet/fee_estimator.go b/lnwallet/fee_estimator.go
index b75d5b804..1c739b553 100644
--- a/lnwallet/fee_estimator.go
+++ b/lnwallet/fee_estimator.go
@@ -1,5 +1,9 @@
 package lnwallet
 
+import (
+	"github.com/roasbeef/btcutil"
+)
+
 // FeeEstimator provides the ability to estimate on-chain transaction fees for
 // various combinations of transaction sizes and desired confirmation time
 // (measured by number of blocks).
@@ -7,12 +11,12 @@ type FeeEstimator interface {
 	// EstimateFeePerByte takes in a target for the number of blocks until
 	// an initial confirmation and returns the estimated fee expressed in
 	// satoshis/byte.
-	EstimateFeePerByte(numBlocks uint32) uint64
+	EstimateFeePerByte(numBlocks uint32) (btcutil.Amount, error)
 
 	// EstimateFeePerWeight takes in a target for the number of blocks
 	// until an initial confirmation and returns the estimated fee
 	// expressed in satoshis/weight.
-	EstimateFeePerWeight(numBlocks uint32) uint64
+	EstimateFeePerWeight(numBlocks uint32) (btcutil.Amount, error)
 }
 
 // StaticFeeEstimator will return a static value for all fee calculation