diff --git a/linebuf.go b/linebuf.go
index f15a0f3..8cee645 100644
--- a/linebuf.go
+++ b/linebuf.go
@@ -52,6 +52,7 @@ func New(opts ...Option) *Scanner {
 	for _, opt := range opts {
 		opt(s)
 	}
+	s.MaxBufSize = max(s.StartBufSize, s.MaxBufSize)
 	s.buf = make([]byte, s.StartBufSize)
 	return s
 }
diff --git a/linebuf_test.go b/linebuf_test.go
index 7781f22..70a3d38 100644
--- a/linebuf_test.go
+++ b/linebuf_test.go
@@ -117,7 +117,7 @@ func TestScanBufferExpand(t *testing.T) {
 }
 
 func TestScanBufferExpandMax(t *testing.T) {
-	sb := New(WithMaxBufSize(16))
+	sb := New(WithStartBufSize(16), WithMaxBufSize(16))
 
 	err := sb.expand(16)
 	require.ErrorIs(t, err, ErrTokenTooLong)