diff --git a/Sources/SwiftMath/MathRender/MTFontManager.swift b/Sources/SwiftMath/MathRender/MTFontManager.swift
index 6644098..7f86008 100644
--- a/Sources/SwiftMath/MathRender/MTFontManager.swift
+++ b/Sources/SwiftMath/MathRender/MTFontManager.swift
@@ -11,7 +11,7 @@ import Foundation
 
 public class MTFontManager {
     
-    static public var manager:MTFontManager? = nil
+    static public private(set) var manager:MTFontManager! = nil
     
     let kDefaultFontSize = CGFloat(20)