diff --git a/Sources/Flow/Internal/Layout.swift b/Sources/Flow/Internal/Layout.swift
index b8536818..92f0cb39 100644
--- a/Sources/Flow/Internal/Layout.swift
+++ b/Sources/Flow/Internal/Layout.swift
@@ -66,7 +66,7 @@ struct FlowLayout: Sendable {
         var size = lines
             .map(\.size)
             .reduce(.zero, breadth: max, depth: +)
-        size[.vertical] += lines.sum(of: \.leadingSpace)
+        size[axis] += lines.sum(of: \.leadingSpace)
         return CGSize(size: size, axis: axis)
     }