diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2022-08-09  Facundo Domínguez <facundo.dominguez@tweag.io> 0.5.5
+
+* Relax dependency bounds to build with ghc9 (#40).
+
 2019-05-12  Facundo Domínguez <facundo.dominguez@tweag.io> 0.5.4
 
 * Fix documentation typo (#39).
diff --git a/network-transport.cabal b/network-transport.cabal
--- a/network-transport.cabal
+++ b/network-transport.cabal
@@ -1,6 +1,6 @@
 Name:          network-transport
-Version:       0.5.4
-Cabal-Version: >=1.6
+Version:       0.5.5
+Cabal-Version: >=1.10
 Build-Type:    Simple
 License:       BSD3
 License-File:  LICENSE
@@ -66,8 +66,8 @@
 Library
   Build-Depends:   base >= 4.6 && < 5,
                    binary >= 0.5 && < 0.9,
-                   bytestring >= 0.9 && < 0.11,
-                   hashable >= 1.2.0.5 && < 1.4,
+                   bytestring >= 0.9 && < 0.12,
+                   hashable >= 1.2.0.5 && < 1.5,
                    transformers >= 0.2 && < 0.6,
                    deepseq >= 1.0 && < 1.5
   if impl(ghc < 7.6)
@@ -75,7 +75,7 @@
   Exposed-Modules: Network.Transport,
                    Network.Transport.Util
                    Network.Transport.Internal
-  Extensions:      ForeignFunctionInterface,
+  Other-Extensions: ForeignFunctionInterface,
                    RankNTypes,
                    ScopedTypeVariables,
                    DeriveDataTypeable,
@@ -83,5 +83,6 @@
                    CPP
   GHC-Options:     -Wall -fno-warn-unused-do-bind
   HS-Source-Dirs:  src
+  Default-Language: Haskell2010
   if os(win32)
       extra-libraries: ws2_32