diff --git a/TODO.txt b/TODO.txt
index aad8838..081cdda 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -1,4 +1,3 @@
-Result should be Failed by default
 Test RuneReader
 Test Regexp
 Add SPDX tags
diff --git a/gigaparsec.go b/gigaparsec.go
index 2f181e6..e07bd31 100644
--- a/gigaparsec.go
+++ b/gigaparsec.go
@@ -10,23 +10,23 @@ import (
 )
 
 type Result[In, Out any] struct {
-	consumed, failed bool
-	value            Out
-	next             State[In]
-	message          Message
+	consumed, succeeded bool
+	value               Out
+	next                State[In]
+	message             Message
 }
 
 func Fail[In, Out any](consumed bool, msg Message) Result[In, Out] {
 	return Result[In, Out]{
-		consumed: consumed,
-		failed:   true,
-		message:  msg,
+		consumed:  consumed,
+		succeeded: false,
+		message:   msg,
 	}
 }
 
-func (r Result[In, Out]) Failed() (ok, consumed bool, msg Message) {
-	ok = r.failed
-	if ok {
+func (r Result[In, Out]) Failed() (failed, consumed bool, msg Message) {
+	failed = !r.succeeded
+	if failed {
 		consumed = r.consumed
 		msg = r.message
 	}
@@ -35,17 +35,17 @@ func (r Result[In, Out]) Failed() (ok, consumed bool, msg Message) {
 
 func Succeed[In, Out any](consumed bool, value Out, next State[In], msg Message) Result[In, Out] {
 	return Result[In, Out]{
-		failed:   false,
-		value:    value,
-		consumed: consumed,
-		next:     next,
-		message:  msg,
+		succeeded: true,
+		value:     value,
+		consumed:  consumed,
+		next:      next,
+		message:   msg,
 	}
 }
 
-func (r Result[In, Out]) Succeeded() (ok, consumed bool, value Out, next State[In], msg Message) {
-	ok = !r.failed
-	if ok {
+func (r Result[In, Out]) Succeeded() (succeeded, consumed bool, value Out, next State[In], msg Message) {
+	succeeded = r.succeeded
+	if succeeded {
 		consumed = r.consumed
 		value = r.value
 		next = r.next
diff --git a/parser_test.go b/parser_test.go
index 9f8464c..94be345 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -56,8 +56,10 @@ func TestSlice(t *testing.T) {
 		r := ptest.ErrReaderAt(expectedErr)
 		c := cursor.NewReaderAt(r)
 		s := rapid.SliceOfN(rapid.Byte(), 0, 100).Draw(t, "s")
-		_, err := gigaparsec.Slice(s)(gigaparsec.MakeState(c))
+		result, err := gigaparsec.Slice(s)(gigaparsec.MakeState(c))
+		failed, _, _ := result.Failed()
 		test.ErrorIs(t, err, expectedErr)
+		test.True(t, failed)
 	}))
 	t.Run("succeeds when contents match", rapid.MakeCheck(func(t *rapid.T) {
 		input := rapid.SliceOfN(rapid.Byte(), 1, -1).Draw(t, "input")