diff --git a/macos/Sources/Ghostty/SurfaceView.swift b/macos/Sources/Ghostty/SurfaceView.swift
index c786afd3b..0252b5a42 100644
--- a/macos/Sources/Ghostty/SurfaceView.swift
+++ b/macos/Sources/Ghostty/SurfaceView.swift
@@ -242,7 +242,11 @@ extension Ghostty {
         // to the app level and it is set from there.
         @Published var title: String = "👻"
 
-        @Published var cellSize: NSSize = .init()
+        // The cell size of this surface. This is set by the core when the
+        // surface is first created and any time the cell size changes (i.e.
+        // when the font size changes). This is used to allow windows to be
+        // resized in discrete steps of a single cell.
+        @Published var cellSize: NSSize = .zero
 
         // An initial size to request for a window. This will only affect
         // then the view is moved to a new window.