diff --git a/buildbox.cabal b/buildbox.cabal
--- a/buildbox.cabal
+++ b/buildbox.cabal
@@ -1,5 +1,5 @@
 Name:                buildbox
-Version:             2.1.4.2
+Version:             2.1.4.3
 License:             BSD3
 License-file:        LICENSE
 Author:              Ben Lippmeier
@@ -26,7 +26,7 @@
         time           >= 1.2 && < 1.5,
         directory      >= 1.1 && < 1.3,
         bytestring     >= 0.9 && < 0.11,
-        mtl            == 2.1.*,
+        mtl            == 2.2.*,
         old-locale     == 1.0.*,
         process        >= 1.2 && < 1.3,
         random         == 1.0.*,