diff --git a/fsm/stateparser/stateparser.go b/fsm/stateparser/stateparser.go
index f1e78ab1..0e11b5c0 100644
--- a/fsm/stateparser/stateparser.go
+++ b/fsm/stateparser/stateparser.go
@@ -14,6 +14,8 @@ import (
 	"github.com/lightninglabs/loop/instantout/reservation"
 )
 
+var errInvalidFSMSelector = errors.New("missing or unknown fsm selector")
+
 func main() {
 	if err := run(); err != nil {
 		fmt.Println(err)
@@ -35,35 +37,34 @@ func run() error {
 		return err
 	}
 
-	switch *stateMachine {
+	states, err := getStates(*stateMachine)
+	if err != nil {
+		return err
+	}
+
+	return writeMermaidFile(fp, states)
+}
+
+func getStates(stateMachine string) (fsm.States, error) {
+	switch stateMachine {
 	case "example":
 		exampleFSM := &fsm.ExampleFSM{}
-		err = writeMermaidFile(fp, exampleFSM.GetStates())
-		if err != nil {
-			return err
-		}
+		return exampleFSM.GetStates(), nil
 
 	case "reservation":
 		reservationFSM := &reservation.FSM{}
-		err = writeMermaidFile(fp, reservationFSM.GetServerInitiatedReservationStates())
-		if err != nil {
-			return err
-		}
+		return reservationFSM.GetServerInitiatedReservationStates(), nil
 
 	case "instantout":
-		instantout := &instantout.FSM{}
-		err = writeMermaidFile(fp, instantout.GetV1ReservationStates())
-		if err != nil {
-			return err
-		}
+		instantOutFSM := &instantout.FSM{}
+		return instantOutFSM.GetV1ReservationStates(), nil
 
 	default:
-		fmt.Println("Missing or wrong argument: fsm must be one of:")
-		fmt.Println("\treservations")
-		fmt.Println("\texample")
+		return nil, fmt.Errorf(
+			"%w %q; supported selectors: example, instantout, reservation",
+			errInvalidFSMSelector, stateMachine,
+		)
 	}
-
-	return nil
 }
 
 func writeMermaidFile(filename string, states fsm.States) error {
diff --git a/instantout/reservation/reservation_fsm.md b/instantout/reservation/reservation_fsm.md
index 1eefb5c6..6a48d367 100644
--- a/instantout/reservation/reservation_fsm.md
+++ b/instantout/reservation/reservation_fsm.md
@@ -2,20 +2,28 @@
 stateDiagram-v2
 [*] --> Init: OnServerRequest
 Confirmed
-Confirmed --> SpendBroadcasted: OnSpendBroadcasted
-Confirmed --> TimedOut: OnTimedOut
+Confirmed --> Confirmed: OnError
+Confirmed --> Locked: OnLocked
 Confirmed --> Confirmed: OnRecover
+Confirmed --> Spent: OnSpent
+Confirmed --> TimedOut: OnTimedOut
 Failed
 Init
 Init --> WaitForConfirmation: OnBroadcast
-Init --> Failed: OnRecover
 Init --> Failed: OnError
-SpendBroadcasted
-SpendBroadcasted --> SpendConfirmed: OnSpendConfirmed
-SpendConfirmed
+Init --> Failed: OnRecover
+Locked
+Locked --> Locked: OnError
+Locked --> Locked: OnRecover
+Locked --> Spent: OnSpent
+Locked --> TimedOut: OnTimedOut
+Locked --> Confirmed: OnUnlocked
+Spent
+Spent --> Spent: OnSpent
 TimedOut
+TimedOut --> TimedOut: OnTimedOut
 WaitForConfirmation
-WaitForConfirmation --> WaitForConfirmation: OnRecover
 WaitForConfirmation --> Confirmed: OnConfirmed
+WaitForConfirmation --> WaitForConfirmation: OnRecover
 WaitForConfirmation --> TimedOut: OnTimedOut
 ```
\ No newline at end of file
diff --git a/scripts/fsm-generate.sh b/scripts/fsm-generate.sh
index 4ab2d74c..0f78fc76 100755
--- a/scripts/fsm-generate.sh
+++ b/scripts/fsm-generate.sh
@@ -1,4 +1,6 @@
 #!/usr/bin/env bash
+set -euo pipefail
+
 go run ./fsm/stateparser/stateparser.go --out ./fsm/example_fsm.md --fsm example
-go run ./fsm/stateparser/stateparser.go --out ./reservation/reservation_fsm.md --fsm reservation
-go run ./fsm/stateparser/stateparser.go --out ./instantout/fsm.md --fsm instantout
\ No newline at end of file
+go run ./fsm/stateparser/stateparser.go --out ./instantout/reservation/reservation_fsm.md --fsm reservation
+go run ./fsm/stateparser/stateparser.go --out ./instantout/fsm.md --fsm instantout