diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,6 @@
+## 0.5.0.1
+ * Bump upper bound for `mtl`
+
 ## 0.5.0.0
 
 * Add `isNotAbsolute` policy and change `static` and `staticPolicy` to 
diff --git a/wai-middleware-static.cabal b/wai-middleware-static.cabal
--- a/wai-middleware-static.cabal
+++ b/wai-middleware-static.cabal
@@ -1,5 +1,5 @@
 Name:                wai-middleware-static
-Version:             0.5.0.0
+Version:             0.5.0.1
 Synopsis:            WAI middleware that serves requests to static files.
 Homepage:            https://github.com/scotty-web/scotty
 Bug-reports:         https://github.com/scotty-web/scotty/issues
@@ -29,7 +29,7 @@
                        directory        >= 1.2.0.1  && < 1.3,
                        filepath         >= 1.3.0.1  && < 1.4,
                        http-types       >= 0.8.2    && < 0.9,
-                       mtl              >= 2.1.2    && < 2.2,
+                       mtl              >= 2.1.2    && < 2.3,
                        text             >= 0.11.3.1 && < 1.2,
                        wai              >= 2.0.0    && < 2.2