diff --git a/fltkhs.cabal b/fltkhs.cabal
--- a/fltkhs.cabal
+++ b/fltkhs.cabal
@@ -1,5 +1,5 @@
 name : fltkhs
-version : 0.5.3.8
+version : 0.5.3.9
 synopsis : FLTK bindings
 description: Low level bindings for the FLTK GUI toolkit. For installation and quick start instruction please scroll all the way down to the README.
 license : MIT
diff --git a/src/Graphics/UI/FLTK/LowLevel/FL.chs b/src/Graphics/UI/FLTK/LowLevel/FL.chs
--- a/src/Graphics/UI/FLTK/LowLevel/FL.chs
+++ b/src/Graphics/UI/FLTK/LowLevel/FL.chs
@@ -771,7 +771,7 @@
 getFontName f = getFontNameWithAttributes' f
 {# fun Fl_get_font_sizes as getFontSizes'
        { cFromFont `Font', id `Ptr (Ptr CInt)' } -> `CInt' #}
-getFontSizes :: Font -> IO [Int]
+getFontSizes :: Font -> IO [FontSize]
 getFontSizes font = do
    arrPtr <- (newArray [] :: IO (Ptr (Ptr CInt)))
    arrLength <- getFontSizes' font arrPtr
@@ -786,7 +786,7 @@
                return size
            )
            [0 .. ((fromIntegral arrLength) - 1)]
-     return (map fromIntegral sizes)
+     return (map FontSize sizes)
 
 {# fun Fl_set_font_by_string as setFontToString
        { cFromFont `Font', unsafeToCString `T.Text' } -> `()' supressWarningAboutRes #}