diff --git a/app/BigFont.hs b/app/BigFont.hs
index 44a6326..25848d5 100644
--- a/app/BigFont.hs
+++ b/app/BigFont.hs
@@ -6,7 +6,7 @@ import Data.Maybe
 import Data.List (intersperse, transpose)
 
 bigText :: String -> [String]
-bigText = map concat . transpose . intersperse sep . mapMaybe \x -> Map.lookup x letters
+bigText = map concat . transpose . intersperse sep . mapMaybe (`Map.lookup` letters)
 
 sep :: [String]
 sep = [" " ," " ," " ," " ," "]
diff --git a/app/Main.hs b/app/Main.hs
index 01dcab2..82c4f44 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -8,6 +8,7 @@ import Data.List.NonEmpty qualified as NonEmpty
 import Data.Map (Map)
 import Data.Map qualified as Map
 import Graphics.Vty
+import Graphics.Vty.CrossPlatform
 import Data.Ord (clamp)
 import System.Directory (listDirectory)
 import System.Environment (getArgs)
diff --git a/app/Model.hs b/app/Model.hs
index 305b217..32d3b9f 100644
--- a/app/Model.hs
+++ b/app/Model.hs
@@ -172,7 +172,7 @@ enterLoc world name box dir@(dy,dx) offset =
         go y x = Just
           (Location name' y x,
            fromIntegral faceSize * offset
-           - fromIntegral ((abs dy *x + abs dx*y)))
+           - fromIntegral (abs dy *x + abs dx*y))
 
         ((ylo,xlo),(yhi,xhi)) = bounds (boxWalls world box)
 
diff --git a/app/Parser.hs b/app/Parser.hs
index 8b57754..483ecff 100644
--- a/app/Parser.hs
+++ b/app/Parser.hs
@@ -126,7 +126,7 @@ parseColor =
 walls :: [String] -> UArray Coord Bool
 walls rows = listArray ((ylo,xlo),(yhi,xhi)) (map ('▓'==) (concat rows))
   where
-    width = length (head rows)
+    width = case rows of x:_ -> length x; [] -> 0
     height = length rows
     ylo = - ((height - 1) `div` 2)
     yhi = height `div` 2
@@ -134,7 +134,7 @@ walls rows = listArray ((ylo,xlo),(yhi,xhi)) (map ('▓'==) (concat rows))
     xhi = width `div` 2
 
 mkRange :: Int -> (Int, Int)
-mkRange n = (-(n-1)`div`2, n`div`2)
+mkRange n = (-((n-1)`div`2), n`div`2)
 
 findLocs :: Char -> [[Char]] -> [(Char, Location)]
 findLocs name xs =
diff --git a/parabox.cabal b/parabox.cabal
index 5084f74..4e9aa13 100644
--- a/parabox.cabal
+++ b/parabox.cabal
@@ -24,6 +24,13 @@ executable parabox
     default-extensions: ImportQualifiedPost, BlockArguments, LambdaCase
 
     ghc-options:      -threaded
-    build-depends:    base ^>=4.17.0.0, array, containers, vty, directory, filepath
+    build-depends:
+        array,
+        base ^>={4.17, 4.18, 4.19, 4.20},
+        containers,
+        directory,
+        filepath,
+        vty-crossplatform,
+        vty ^>= 6.2,
     hs-source-dirs:   app
     default-language: Haskell2010