diff --git a/Sources/SwiftMath/MathBundle/MathFont.swift b/Sources/SwiftMath/MathBundle/MathFont.swift
index d7abd7c..129c350 100644
--- a/Sources/SwiftMath/MathBundle/MathFont.swift
+++ b/Sources/SwiftMath/MathBundle/MathFont.swift
@@ -104,7 +104,7 @@ private class BundleManager {
         guard CTFontManagerRegisterGraphicsFont(defaultCGFont, &errorRef) else {
             throw FontError.registerFailed
         }
-        print("mathFonts bundle resource: \(mathFont.rawValue), font: \(defaultCGFont.fullName) registered.")
+        print("mathFonts bundle resource: \(mathFont.rawValue), font: \(defaultCGFont.fullName!) registered.")
     }
     
     private func registerMathTable(mathFont: MathFont) throws {