diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,11 @@
 
 ## [Unreleased]
 
+## [1.5.0] - 2025-07-23
+
+### Changed
+- Make FormData backend monadic (breaking change) (#59)
+
 ## [1.4.0] - 2025-05-19
 
 ### Added
@@ -76,7 +81,8 @@
 - Extracted webgear-core from webgear-server
 - New arrow based API
 
-[Unreleased]: https://github.com/haskell-webgear/webgear/compare/v1.4.0...HEAD
+[Unreleased]: https://github.com/haskell-webgear/webgear/compare/v1.5.0...HEAD
+[1.5.0]: https://github.com/haskell-webgear/webgear/releases/tag/v1.5.0
 [1.4.0]: https://github.com/haskell-webgear/webgear/releases/tag/v1.4.0
 [1.3.1]: https://github.com/haskell-webgear/webgear/releases/tag/v1.3.1
 [1.3.0]: https://github.com/haskell-webgear/webgear/releases/tag/v1.3.0
diff --git a/src/WebGear/Core/MIMETypes.hs b/src/WebGear/Core/MIMETypes.hs
--- a/src/WebGear/Core/MIMETypes.hs
+++ b/src/WebGear/Core/MIMETypes.hs
@@ -59,9 +59,9 @@
 --------------------------------------------------------------------------------
 
 -- | The multipart/form-data MIME type
-data FormData a = FormData
+data FormData m a = FormData
   { parseOptions :: Wai.Parse.ParseRequestBodyOptions
-  , backendOptions :: Wai.Parse.BackEnd a
+  , backendOptions :: m (Wai.Parse.BackEnd a)
   }
 
 {- | Result of parsing a multipart/form-data body from a request.
@@ -72,8 +72,8 @@
   , formDataFiles :: [Wai.Parse.File a]
   }
 
-instance MIMEType (FormData a) where
-  mimeType :: FormData a -> HTTP.MediaType
+instance MIMEType (FormData m a) where
+  mimeType :: FormData m a -> HTTP.MediaType
   mimeType _ = "multipart/form-data"
   {-# INLINE mimeType #-}
 
diff --git a/webgear-core.cabal b/webgear-core.cabal
--- a/webgear-core.cabal
+++ b/webgear-core.cabal
@@ -1,7 +1,7 @@
 cabal-version:       2.4
 
 name:                webgear-core
-version:             1.4.0
+version:             1.5.0
 synopsis:            Composable, type-safe library to build HTTP APIs
 description:
         WebGear is a library to for building composable, type-safe HTTP APIs.