diff --git a/binaries/data/mods/public/gui/pregame/mainmenu.js b/binaries/data/mods/public/gui/pregame/mainmenu.js
index 309e62a957..92a23d43ab 100644
--- a/binaries/data/mods/public/gui/pregame/mainmenu.js
+++ b/binaries/data/mods/public/gui/pregame/mainmenu.js
@@ -212,7 +212,7 @@ function openMenu(newSubmenu, position, buttonHeight, numButtons)
 	var submenu = Engine.GetGUIObjectByName("submenu");
 	var top = position - MARGIN;
 	var bottom = position + ((buttonHeight + MARGIN) * numButtons);
-	submenu.size = submenu.size.left + " " + top + " " + submenu.size.right + " " + bottom;
+	submenu.size = new GUISize(submenu.size.left, top, submenu.size.right, bottom);
 
 	// Blend in right border of main menu into the left border of the submenu
 	blendSubmenuIntoMain(top, bottom);
diff --git a/binaries/data/mods/public/gui/session/input.js b/binaries/data/mods/public/gui/session/input.js
index cf8e41898e..34bd06f36f 100644
--- a/binaries/data/mods/public/gui/session/input.js
+++ b/binaries/data/mods/public/gui/session/input.js
@@ -423,7 +423,7 @@ function updateBandbox(bandbox, ev, hidden)
 
 	let scale = +Engine.ConfigDB_GetValue("user", "gui.scale");
 
-	bandbox.size = [x0 * scale, y0 * scale, x1 * scale, y1 * scale].join(" ");
+	bandbox.size = new GUISize(x0 * scale, y0 * scale, x1 * scale, y1 * scale);
 	bandbox.hidden = hidden;
 
 	return [x0, y0, x1, y1];