diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+## Req 0.4.0
+
+* Added the `Req` monad and `runReq` function to run it. This allows to use
+  `req` without defining new (orphan) instances.
+
 ## Req 0.3.1
 
 * Added `basicAuthUnsafe`.
diff --git a/Network/HTTP/Req.hs b/Network/HTTP/Req.hs
--- a/Network/HTTP/Req.hs
+++ b/Network/HTTP/Req.hs
@@ -95,6 +95,7 @@
 {-# LANGUAGE FlexibleInstances          #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE KindSignatures             #-}
+{-# LANGUAGE MultiParamTypeClasses      #-}
 {-# LANGUAGE OverloadedStrings          #-}
 {-# LANGUAGE RankNTypes                 #-}
 {-# LANGUAGE RecordWildCards            #-}
@@ -123,6 +124,8 @@
     -- $embedding-requests
   , MonadHttp  (..)
   , HttpConfig (..)
+  , Req
+  , runReq
     -- * Request
     -- ** Method
     -- $method
@@ -213,7 +216,10 @@
 import Control.Arrow (first, second)
 import Control.Exception (Exception, try, handle, throwIO)
 import Control.Monad
+import Control.Monad.Base
 import Control.Monad.IO.Class
+import Control.Monad.Reader
+import Control.Monad.Trans.Control
 import Control.Retry
 import Data.Aeson (ToJSON (..), FromJSON (..))
 import Data.ByteString (ByteString)
@@ -581,6 +587,42 @@
     x { L.proxy                   = httpConfigProxy
       , L.redirectCount           = httpConfigRedirectCount
       , LI.requestManagerOverride = httpConfigAltManager }
+
+-- | A monad that allows to run 'req' in any 'IO'-enabled monad without
+-- having to define new instances.
+--
+-- @since 0.4.0
+
+newtype Req a = Req (ReaderT HttpConfig IO a)
+  deriving ( Functor
+           , Applicative
+           , Monad
+           , MonadIO )
+
+instance MonadBase IO Req where
+  liftBase = liftIO
+
+instance MonadBaseControl IO Req where
+  type StM Req a = a
+  liftBaseWith f = Req . ReaderT $ \r -> f (runReq r)
+  {-# INLINEABLE liftBaseWith #-}
+  restoreM       = Req . ReaderT . const . return
+  {-# INLINEABLE restoreM #-}
+
+instance MonadHttp Req where
+  handleHttpException = Req . lift . throwIO
+  getHttpConfig       = Req ask
+
+-- | Run a computation in the 'Req' monad with the given 'HttpConfig'. In
+-- case of exceptional situation an 'HttpException' will be thrown.
+--
+-- @since 0.4.0
+
+runReq :: MonadIO m
+  => HttpConfig        -- ^ 'HttpConfig' to use
+  -> Req a             -- ^ Computation to run
+  -> m a
+runReq config (Req m) = liftIO (runReaderT m config)
 
 ----------------------------------------------------------------------------
 -- Request—Method
diff --git a/httpbin-tests/Network/HTTP/ReqSpec.hs b/httpbin-tests/Network/HTTP/ReqSpec.hs
--- a/httpbin-tests/Network/HTTP/ReqSpec.hs
+++ b/httpbin-tests/Network/HTTP/ReqSpec.hs
@@ -9,8 +9,9 @@
   ( spec )
 where
 
-import Control.Exception (throwIO)
+import Control.Exception
 import Control.Monad.Reader
+import Control.Monad.Trans.Control
 import Data.Aeson (Value (..), ToJSON (..), object, (.=))
 import Data.Default.Class
 import Data.IORef
@@ -41,17 +42,18 @@
 spec :: Spec
 spec = do
 
-  describe "exception throwing on non 2xx-status codes" $
-    it "throws indeed for non-2xx" $ do
-      let selector :: HttpException -> Bool
-          selector (VanillaHttpException
-                    (L.HttpExceptionRequest _
-                     (L.StatusCodeException response chunk))) =
-            L.responseStatus response == Y.status404 && not (B.null chunk)
-          selector _ = False
+  describe "exception throwing on non-2xx status codes" $
+    it "throws indeed for non-2xx" $
       req GET (httpbin /: "foo") NoReqBody ignoreResponse mempty
-        `shouldThrow` selector
+        `shouldThrow` selector404
 
+  describe "exception throwing on non-2xx status codes (Req monad)" $
+    it "throws indeed for non-2xx" $
+      asIO . runReq def $
+        liftBaseWith $ \run ->
+          run (req GET (httpbin /: "foo") NoReqBody ignoreResponse mempty)
+            `shouldThrow` selector404
+
   describe "response check via httpConfigCheckResponse" $
     context "if it's set to always throw" $
       it "throws indeed" $
@@ -401,6 +403,15 @@
         NoReqBody ignoreResponse mempty
       responseStatusCode r `shouldBe` code
 
+-- | Exception selector that selects only 404 “Not found” exceptions.
+
+selector404 :: HttpException -> Bool
+selector404 (VanillaHttpException
+             (L.HttpExceptionRequest _
+              (L.StatusCodeException response chunk))) =
+  L.responseStatus response == Y.status404 && not (B.null chunk)
+selector404 _ = False
+
 -- | Empty JSON 'Object'.
 
 emptyObject :: Value
@@ -410,3 +421,9 @@
 
 reflectJSON :: ToJSON a => a -> Text
 reflectJSON = T.decodeUtf8 . BL.toStrict . A.encode
+
+-- | Clarify to the type checker that the inner computation is in the 'IO'
+-- monad.
+
+asIO :: IO a -> IO a
+asIO = id
diff --git a/req.cabal b/req.cabal
--- a/req.cabal
+++ b/req.cabal
@@ -1,5 +1,5 @@
 name:                 req
-version:              0.3.1
+version:              0.4.0
 cabal-version:        >= 1.18
 tested-with:          GHC==7.8.4, GHC==7.10.3, GHC==8.0.2, GHC==8.2.1
 license:              BSD3
@@ -39,11 +39,13 @@
                     , http-client      >= 0.5    && < 0.6
                     , http-client-tls  >= 0.3.2  && < 0.4
                     , http-types       >= 0.8    && < 10.0
+                    , monad-control    >= 1.0    && < 1.1
                     , mtl              >= 2.0    && < 3.0
                     , retry            >= 0.7    && < 0.8
                     , text             >= 0.2    && < 1.3
                     , time             >= 1.2    && < 1.9
                     , transformers     >= 0.4    && < 0.6
+                    , transformers-base
   if !impl(ghc >= 8.0)
     build-depends:    semigroups   == 0.18.*
   exposed-modules:    Network.HTTP.Req
@@ -92,6 +94,7 @@
                     , hspec            >= 2.0    && < 3.0
                     , http-client      >= 0.5    && < 0.6
                     , http-types       >= 0.8    && < 10.0
+                    , monad-control    >= 1.0    && < 1.1
                     , mtl              >= 2.0    && < 3.0
                     , req
                     , retry            >= 0.7    && < 0.8