diff --git a/warp.cabal b/warp.cabal
--- a/warp.cabal
+++ b/warp.cabal
@@ -1,5 +1,5 @@
 Name:                warp
-Version:             2.1.5.1
+Version:             2.1.5.2
 Synopsis:            A fast, light-weight web server for WAI applications.
 License:             MIT
 License-file:        LICENSE
@@ -49,7 +49,7 @@
                    , lifted-base               >= 0.1
                    , network-conduit           >= 0.5      && < 1.2
                    , simple-sendfile           >= 0.2.7    && < 0.3
-                   , transformers              >= 0.2.2    && < 0.4
+                   , transformers              >= 0.2.2
                    , unix-compat               >= 0.2
                    , void
                    , wai                       >= 2.1      && < 2.2
@@ -136,7 +136,7 @@
                    , lifted-base               >= 0.1
                    , network-conduit
                    , simple-sendfile           >= 0.2.4    && < 0.3
-                   , transformers              >= 0.2.2    && < 0.4
+                   , transformers              >= 0.2.2
                    , unix-compat               >= 0.2
                    , void
                    , wai