diff --git a/servant-swagger-ui-core/servant-swagger-ui-core.cabal b/servant-swagger-ui-core/servant-swagger-ui-core.cabal
index fcca9f7..3c45709 100644
--- a/servant-swagger-ui-core/servant-swagger-ui-core.cabal
+++ b/servant-swagger-ui-core/servant-swagger-ui-core.cabal
@@ -36,7 +36,6 @@ library
   ghc-options:      -Wall
   build-depends:
       base                 >=4.7      && <4.15
-    , aeson                >=0.8.0.2  && <1.6
     , blaze-markup         >=0.7.0.2  && <0.9
     , bytestring           >=0.10.4.0 && <0.11
     , http-media           >=0.7.1.3  && <0.9
diff --git a/servant-swagger-ui-core/src/Servant/Swagger/UI/Core.hs b/servant-swagger-ui-core/src/Servant/Swagger/UI/Core.hs
index 0b9a1bc..19ad54f 100644
--- a/servant-swagger-ui-core/src/Servant/Swagger/UI/Core.hs
+++ b/servant-swagger-ui-core/src/Servant/Swagger/UI/Core.hs
@@ -23,7 +23,7 @@
 --     :\<|> "cat" :> Capture ":name" CatName :> Get '[JSON] Cat
 --
 -- -- | API type with bells and whistles, i.e. schema file and swagger-ui.
--- type API = 'SwaggerSchemaUI' "swagger-ui" "swagger.json"
+-- type API = 'SwaggerSchemaUI' "swagger-ui" "swagger.json" Swagger
 --     :\<|> BasicAPI
 --
 -- -- | Servant server for an API
@@ -46,7 +46,6 @@ module Servant.Swagger.UI.Core (
     Handler,
     ) where
 
-import Data.Aeson                     (ToJSON (..), Value)
 import Data.ByteString                (ByteString)
 import GHC.TypeLits                   (KnownSymbol, Symbol, symbolVal)
 import Network.Wai.Application.Static (embeddedSettings, staticApp)
@@ -58,7 +57,7 @@ import qualified Data.Text as T
 
 -- | Swagger schema + ui api.
 --
--- @SwaggerSchemaUI "swagger-ui" "swagger.json"@ will result into following hierarchy:
+-- @SwaggerSchemaUI "swagger-ui" "swagger.json" Swagger@ will result into following hierarchy:
 --
 -- @
 -- \/swagger.json
@@ -67,10 +66,11 @@ import qualified Data.Text as T
 -- \/swagger-ui\/...
 -- @
 --
--- This type does not actually force served type to be @Swagger@ from @swagger2@ package,
--- it could be arbitrary @aeson@ 'Value'.
-type SwaggerSchemaUI (dir :: Symbol) (schema :: Symbol) =
-    SwaggerSchemaUI' dir (schema :> Get '[JSON] Value)
+-- The third type parameter specifies which Haskell datatype contains the Swagger
+-- description. Typical instantiations are @Swagger@ from the @swagger2@ package,
+-- and @OpenApi@ from the @openapi3@ package.
+type SwaggerSchemaUI (dir :: Symbol) (schema :: Symbol) (a :: *) =
+    SwaggerSchemaUI' dir (schema :> Get '[JSON] a)
 
 -- | Use 'SwaggerSchemaUI'' when you need even more control over
 -- where @swagger.json@ is served (e.g. subdirectory).
@@ -103,11 +103,11 @@ instance (KnownSymbol dir, HasLink api, Link ~ MkLink api Link, IsElem api api)
         proxyApi = Proxy :: Proxy api
 
 swaggerSchemaUIServerImpl
-    :: (Monad m, ServerT api m ~ m Value, ToJSON a)
+    :: (Monad m, ServerT api m ~ m a)
     => T.Text -> [(FilePath, ByteString)]
     -> a -> ServerT (SwaggerSchemaUI' dir api) m
 swaggerSchemaUIServerImpl indexTemplate files swagger
-  = swaggerSchemaUIServerImpl' indexTemplate files $ return $ toJSON swagger
+  = swaggerSchemaUIServerImpl' indexTemplate files $ return $ swagger
 
 -- | Use a custom server to serve the Swagger spec source.
 swaggerSchemaUIServerImpl'
diff --git a/servant-swagger-ui-example/src/Main.hs b/servant-swagger-ui-example/src/Main.hs
index dcd1dd7..dd77679 100644
--- a/servant-swagger-ui-example/src/Main.hs
+++ b/servant-swagger-ui-example/src/Main.hs
@@ -16,7 +16,7 @@ import Prelude ()
 import Prelude.Compat
 
 import Control.Lens       hiding ((.=))
-import Data.Aeson         (FromJSON, ToJSON, Value)
+import Data.Aeson         (FromJSON, ToJSON)
 import Data.Maybe         (fromMaybe)
 import Data.String        (IsString (..))
 import Data.Text          (Text)
@@ -136,13 +136,13 @@ type BasicAPI = Get '[PlainText, JSON] Text
 
 type API =
     -- this serves both: swagger.json and swagger-ui
-    SwaggerSchemaUI "swagger-ui" "swagger.json"
+    SwaggerSchemaUI "swagger-ui" "swagger.json" Swagger
     :<|> BasicAPI
 
 -- To test nested case
 type API' = API
     :<|> "nested" :> API
-    :<|> SwaggerSchemaUI' "foo-ui" ("foo" :> "swagger.json" :> Get '[JSON] Value)
+    :<|> SwaggerSchemaUI' "foo-ui" ("foo" :> "swagger.json" :> Get '[JSON] Swagger)
 
 -- Implementation
 
@@ -174,7 +174,7 @@ server' uiFlavour = server Normal
         -- Unfortunately we have to specify the basePath manually atm.
 
     schemaUiServer
-        :: (Server api ~ Handler Value)
+        :: (Server api ~ Handler Swagger)
         => Swagger -> Server (SwaggerSchemaUI' dir api)
     schemaUiServer = case uiFlavour of
         Original -> swaggerSchemaUIServer
diff --git a/servant-swagger-ui-jensoleg/servant-swagger-ui-jensoleg.cabal b/servant-swagger-ui-jensoleg/servant-swagger-ui-jensoleg.cabal
index 92ad52a..bc536df 100644
--- a/servant-swagger-ui-jensoleg/servant-swagger-ui-jensoleg.cabal
+++ b/servant-swagger-ui-jensoleg/servant-swagger-ui-jensoleg.cabal
@@ -85,7 +85,6 @@ library
   build-depends:    servant-swagger-ui-core >=0.3.5 && <0.4
   build-depends:
       base             >=4.7      && <4.15
-    , aeson            >=0.8.0.2  && <1.6
     , bytestring       >=0.10.4.0 && <0.11
     , file-embed-lzma  >=0        && <0.1
     , servant          >=0.14     && <0.19
diff --git a/servant-swagger-ui-jensoleg/src/Servant/Swagger/UI/JensOleG.hs b/servant-swagger-ui-jensoleg/src/Servant/Swagger/UI/JensOleG.hs
index 3311908..14a04e6 100644
--- a/servant-swagger-ui-jensoleg/src/Servant/Swagger/UI/JensOleG.hs
+++ b/servant-swagger-ui-jensoleg/src/Servant/Swagger/UI/JensOleG.hs
@@ -55,7 +55,6 @@ module Servant.Swagger.UI.JensOleG (
 
 import Servant.Swagger.UI.Core
 
-import Data.Aeson      (ToJSON, Value)
 import Data.ByteString (ByteString)
 import Data.Text       (Text)
 import FileEmbedLzma
@@ -67,7 +66,7 @@ import Servant
 --
 -- See <https://github.com/jensoleg/swagger-ui>
 jensolegSwaggerSchemaUIServer
-    :: (Server api ~ Handler Value, ToJSON a)
+    :: (Server api ~ Handler a)
     => a -> Server (SwaggerSchemaUI' dir api)
 jensolegSwaggerSchemaUIServer =
     swaggerSchemaUIServerImpl jensolegIndexTemplate jensolegFiles
diff --git a/servant-swagger-ui-redoc/servant-swagger-ui-redoc.cabal b/servant-swagger-ui-redoc/servant-swagger-ui-redoc.cabal
index f8f7240..aea7f9c 100644
--- a/servant-swagger-ui-redoc/servant-swagger-ui-redoc.cabal
+++ b/servant-swagger-ui-redoc/servant-swagger-ui-redoc.cabal
@@ -35,7 +35,6 @@ library
   build-depends:    servant-swagger-ui-core >=0.3.5 && <0.4
   build-depends:
       base             >=4.7      && <4.15
-    , aeson            >=0.8.0.2  && <1.6
     , bytestring       >=0.10.4.0 && <0.11
     , file-embed-lzma  >=0        && <0.1
     , servant          >=0.14     && <0.19
diff --git a/servant-swagger-ui-redoc/src/Servant/Swagger/UI/ReDoc.hs b/servant-swagger-ui-redoc/src/Servant/Swagger/UI/ReDoc.hs
index 8c7399e..7bb234a 100644
--- a/servant-swagger-ui-redoc/src/Servant/Swagger/UI/ReDoc.hs
+++ b/servant-swagger-ui-redoc/src/Servant/Swagger/UI/ReDoc.hs
@@ -57,7 +57,6 @@ module Servant.Swagger.UI.ReDoc (
 
 import Servant.Swagger.UI.Core
 
-import Data.Aeson      (ToJSON, Value)
 import Data.ByteString (ByteString)
 import Data.Text       (Text)
 import FileEmbedLzma
@@ -67,7 +66,7 @@ import Servant
 --
 -- See <https://github.com/Rebilly/ReDoc/tree/v1.x>
 redocSchemaUIServer
-    :: (Server api ~ Handler Value, ToJSON a)
+    :: (Server api ~ Handler a)
     => a -> Server (SwaggerSchemaUI' dir api)
 redocSchemaUIServer =
     swaggerSchemaUIServerImpl redocIndexTemplate redocFiles
@@ -80,7 +79,7 @@ redocSchemaUIServer =
 -- redocSchemaUIServerT :: Swagger -> ServerT (SwaggerSchemaUI schema dir) m
 -- @
 redocSchemaUIServerT
-    :: (Monad m, ServerT api m ~ m Value, ToJSON a)
+    :: (Monad m, ServerT api m ~ m a)
     => a -> ServerT (SwaggerSchemaUI' dir api) m
 redocSchemaUIServerT =
     swaggerSchemaUIServerImpl redocIndexTemplate redocFiles
diff --git a/servant-swagger-ui/servant-swagger-ui.cabal b/servant-swagger-ui/servant-swagger-ui.cabal
index 6b30e1d..2b031eb 100644
--- a/servant-swagger-ui/servant-swagger-ui.cabal
+++ b/servant-swagger-ui/servant-swagger-ui.cabal
@@ -45,7 +45,6 @@ library
   build-depends:    servant-swagger-ui-core >=0.3.5 && <0.4
   build-depends:
       base             >=4.7      && <4.15
-    , aeson            >=0.8.0.2  && <1.6
     , bytestring       >=0.10.4.0 && <0.11
     , file-embed-lzma  >=0        && <0.1
     , servant          >=0.14     && <0.19
diff --git a/servant-swagger-ui/src/Servant/Swagger/UI.hs b/servant-swagger-ui/src/Servant/Swagger/UI.hs
index 602dd40..f16c816 100644
--- a/servant-swagger-ui/src/Servant/Swagger/UI.hs
+++ b/servant-swagger-ui/src/Servant/Swagger/UI.hs
@@ -62,7 +62,7 @@ module Servant.Swagger.UI (
 
 import Servant.Swagger.UI.Core
 
-import Data.Aeson      (ToJSON, Value)
+-- import Data.Aeson      (ToJSON, Value)
 import Data.ByteString (ByteString)
 import Data.Text       (Text)
 import FileEmbedLzma
@@ -75,7 +75,7 @@ import Servant
 -- swaggerSchemaUIServer :: OpenApi -> Server (SwaggerSchemaUI schema dir)
 -- @
 swaggerSchemaUIServer
-    :: (Server api ~ Handler Value, ToJSON a)
+    :: (Server api ~ Handler a)
     => a -> Server (SwaggerSchemaUI' dir api)
 swaggerSchemaUIServer =
     swaggerSchemaUIServerImpl swaggerUiIndexTemplate swaggerUiFiles
@@ -89,7 +89,7 @@ swaggerSchemaUIServer =
 -- swaggerSchemaUIServerT :: OpenApi -> ServerT (SwaggerSchemaUI schema dir) m
 -- @
 swaggerSchemaUIServerT
-    :: (Monad m, ServerT api m ~ m Value, ToJSON a)
+    :: (Monad m, ServerT api m ~ m a)
     => a -> ServerT (SwaggerSchemaUI' dir api) m
 swaggerSchemaUIServerT =
     swaggerSchemaUIServerImpl swaggerUiIndexTemplate swaggerUiFiles