diff --git a/htlcswitch/switch.go b/htlcswitch/switch.go
index 27c4e7ca..a41081ce 100644
--- a/htlcswitch/switch.go
+++ b/htlcswitch/switch.go
@@ -348,7 +348,8 @@ func (s *Switch) ProcessContractResolution(msg contractcourt.ResolutionMsg) erro
 
 // SendHTLC is used by other subsystems which aren't belong to htlc switch
 // package in order to send the htlc update. The paymentID used MUST be unique
-// for this HTLC, otherwise the switch might reject it.
+// for this HTLC, and MUST be used only once, otherwise the switch might reject
+// it.
 func (s *Switch) SendHTLC(firstHop lnwire.ShortChannelID, paymentID uint64,
 	htlc *lnwire.UpdateAddHTLC,
 	deobfuscator ErrorDecrypter) ([sha256.Size]byte, error) {
diff --git a/htlcswitch/switch_test.go b/htlcswitch/switch_test.go
index c6ea60a2..73aee0ad 100644
--- a/htlcswitch/switch_test.go
+++ b/htlcswitch/switch_test.go
@@ -1748,16 +1748,6 @@ func TestSwitchSendPayment(t *testing.T) {
 		errChan <- err
 	}()
 
-	go func() {
-		// Send the payment with the same payment hash and same
-		// amount and check that it will be propagated successfully
-		_, err := s.SendHTLC(
-			aliceChannelLink.ShortChanID(), 0, update,
-			newMockDeobfuscator(),
-		)
-		errChan <- err
-	}()
-
 	select {
 	case packet := <-aliceChannelLink.packets:
 		if err := aliceChannelLink.completeCircuit(packet); err != nil {
@@ -1765,29 +1755,13 @@ func TestSwitchSendPayment(t *testing.T) {
 		}
 
 	case err := <-errChan:
-		if err != ErrPaymentInFlight {
+		if err != nil {
 			t.Fatalf("unable to send payment: %v", err)
 		}
 	case <-time.After(time.Second):
 		t.Fatal("request was not propagated to destination")
 	}
 
-	select {
-	case packet := <-aliceChannelLink.packets:
-		if err := aliceChannelLink.completeCircuit(packet); err != nil {
-			t.Fatalf("unable to complete payment circuit: %v", err)
-		}
-
-	case err := <-errChan:
-		t.Fatalf("unable to send payment: %v", err)
-	case <-time.After(time.Second):
-		t.Fatal("request was not propagated to destination")
-	}
-
-	if s.numPendingPayments() != 1 {
-		t.Fatal("wrong amount of pending payments")
-	}
-
 	if s.circuits.NumOpen() != 1 {
 		t.Fatal("wrong amount of circuits")
 	}