diff --git a/wallet/psbt.go b/wallet/psbt.go
index e2d4fe8..1a68a71 100644
--- a/wallet/psbt.go
+++ b/wallet/psbt.go
@@ -134,7 +134,14 @@ func (w *Wallet) FundPsbt(packet *psbt.Packet, account uint32,
 		}
 
 		// We can leverage the fee calculation of the txauthor package
-		// if we provide the selected UTXOs as a coin source.
+		// if we provide the selected UTXOs as a coin source. We just
+		// need to make sure we always return the full list of user-
+		// selected UTXOs rather than a subset, otherwise our change
+		// amount will be off (in case the user selected multiple UTXOs
+		// that are large enough on their own). That's why we use our
+		// own static input source creator instead of the more generic
+		// makeInputSource() that selects a subset that is "large
+		// enough".
 		credits := make([]wtxmgr.Credit, len(txIn))
 		for idx, in := range txIn {
 			utxo := packet.Inputs[idx].WitnessUtxo
@@ -144,7 +151,7 @@ func (w *Wallet) FundPsbt(packet *psbt.Packet, account uint32,
 				PkScript: utxo.PkScript,
 			}
 		}
-		inputSource := makeInputSource(credits)
+		inputSource := constantInputSource(credits)
 
 		// We also need a change source which needs to be able to insert
 		// a new change addresse into the database.
@@ -319,3 +326,30 @@ func (w *Wallet) FinalizePsbt(packet *psbt.Packet) error {
 
 	return nil
 }
+
+// constantInputSource creates an input source function that always returns the
+// static set of user-selected UTXOs.
+func constantInputSource(eligible []wtxmgr.Credit) txauthor.InputSource {
+	// Current inputs and their total value. These won't change over
+	// different invocations as we want our inputs to remain static since
+	// they're selected by the user.
+	currentTotal := btcutil.Amount(0)
+	currentInputs := make([]*wire.TxIn, 0, len(eligible))
+	currentScripts := make([][]byte, 0, len(eligible))
+	currentInputValues := make([]btcutil.Amount, 0, len(eligible))
+
+	for _, credit := range eligible {
+		nextInput := wire.NewTxIn(&credit.OutPoint, nil, nil)
+		currentTotal += credit.Amount
+		currentInputs = append(currentInputs, nextInput)
+		currentScripts = append(currentScripts, credit.PkScript)
+		currentInputValues = append(currentInputValues, credit.Amount)
+	}
+
+	return func(target btcutil.Amount) (btcutil.Amount, []*wire.TxIn,
+		[]btcutil.Amount, [][]byte, error) {
+
+		return currentTotal, currentInputs, currentInputValues,
+			currentScripts, nil
+	}
+}
diff --git a/wallet/psbt_test.go b/wallet/psbt_test.go
index dfb67cd..b9747b2 100644
--- a/wallet/psbt_test.go
+++ b/wallet/psbt_test.go
@@ -68,6 +68,8 @@ func TestFundPsbt(t *testing.T) {
 		feeRateSatPerKB   btcutil.Amount
 		expectedErr       string
 		validatePackage   bool
+		expectedFee       int64
+		expectedChange    int64
 		numExpectedInputs int
 	}{{
 		name: "no outputs provided",
@@ -106,6 +108,8 @@ func TestFundPsbt(t *testing.T) {
 		feeRateSatPerKB:   2000, // 2 sat/byte
 		expectedErr:       "",
 		validatePackage:   true,
+		expectedChange:    1000000 - 150000 - 368,
+		expectedFee:       368,
 		numExpectedInputs: 1,
 	}, {
 		name: "two outputs, two inputs",
@@ -136,6 +140,8 @@ func TestFundPsbt(t *testing.T) {
 		feeRateSatPerKB:   2000, // 2 sat/byte
 		expectedErr:       "",
 		validatePackage:   true,
+		expectedFee:       506,
+		expectedChange:    2000000 - 150000 - 506,
 		numExpectedInputs: 2,
 	}}
 
@@ -296,15 +302,17 @@ func TestFundPsbt(t *testing.T) {
 					txOuts[p2wshIndex].PkScript)
 			}
 
-			// Finally, check the change output size and that it
-			// belongs to the wallet.
-			expectedFee := int64(368)
-			expectedChange := 1000000 - 150000 - expectedFee
-			if txOuts[changeIndex].Value != expectedChange {
+			// Finally, check the change output size and fee.
+			fee := totalIn - totalOut
+			if fee != tc.expectedFee {
+				t.Fatalf("unexpected fee, got %d wanted %d",
+					fee, tc.expectedFee)
+			}
+			if txOuts[changeIndex].Value != tc.expectedChange {
 				t.Fatalf("unexpected change output size, got "+
 					"%d wanted %d",
 					txOuts[changeIndex].Value,
-					expectedChange)
+					tc.expectedChange)
 			}
 		})
 	}