diff --git a/mockery.cabal b/mockery.cabal
--- a/mockery.cabal
+++ b/mockery.cabal
@@ -1,9 +1,9 @@
--- This file has been generated from package.yaml by hpack version 0.5.4.
+-- This file has been generated from package.yaml by hpack version 0.11.0.
 --
 -- see: https://github.com/sol/hpack
 
 name:           mockery
-version:        0.3.2
+version:        0.3.3
 synopsis:       Support functions for automated testing
 description:    Support functions for automated testing
 category:       Testing
@@ -26,6 +26,7 @@
   ghc-options: -Wall
   build-depends:
       base == 4.*
+    , base-compat
     , bytestring
     , temporary
     , directory
@@ -33,6 +34,7 @@
     , logging-facade
   exposed-modules:
       Test.Mockery.Directory
+      Test.Mockery.Environment
       Test.Mockery.Logging
   default-language: Haskell2010
 
@@ -44,6 +46,7 @@
   ghc-options: -Wall
   build-depends:
       base == 4.*
+    , base-compat
     , bytestring
     , temporary
     , directory
@@ -53,5 +56,6 @@
     , hspec == 2.*
   other-modules:
       Test.Mockery.DirectorySpec
+      Test.Mockery.EnvironmentSpec
       Test.Mockery.LoggingSpec
   default-language: Haskell2010
diff --git a/src/Test/Mockery/Environment.hs b/src/Test/Mockery/Environment.hs
new file mode 100644
--- /dev/null
+++ b/src/Test/Mockery/Environment.hs
@@ -0,0 +1,31 @@
+module Test.Mockery.Environment (withEnvironment) where
+
+import           Control.Exception.Base
+import           Control.Monad
+import           System.Environment.Compat
+
+-- |
+-- Run the given action with the specified environment.
+--
+-- Before executing the action, `withEnvironment` backs up the current environment,
+-- clears out the environment, and then applies the supplied environment.
+-- After the action has completed the original environment is restored.
+-- __Note__: The environment is global for a process, so tests that depend on the
+-- environment can no longer be run in parallel.
+withEnvironment :: [(String, String)] -> IO a -> IO a
+withEnvironment environment action = bracket saveEnv restoreEnv $ const action
+  where
+    saveEnv :: IO [(String, String)]
+    saveEnv = do
+      env <- clearEnv
+      forM_ environment $ uncurry setEnv
+      return env
+    restoreEnv :: [(String, String)] -> IO ()
+    restoreEnv env = do
+      _ <- clearEnv
+      forM_ env $ uncurry setEnv
+    clearEnv :: IO [(String, String)]
+    clearEnv = do
+      env <- getEnvironment
+      forM_ env (unsetEnv . fst)
+      return env
diff --git a/test/Test/Mockery/EnvironmentSpec.hs b/test/Test/Mockery/EnvironmentSpec.hs
new file mode 100644
--- /dev/null
+++ b/test/Test/Mockery/EnvironmentSpec.hs
@@ -0,0 +1,24 @@
+module Test.Mockery.EnvironmentSpec where
+
+import           System.Environment.Compat
+import           Test.Hspec
+
+import           Test.Mockery.Environment
+
+spec :: Spec
+spec = describe "withEnvironment" $ do
+  it "hides the environment" $ do
+    withEnvironment [("foo", "bar")] $ do
+      env <- getEnvironment
+      env `shouldMatchList` [("foo", "bar")]
+  it "restores the environment" $ do
+    oldEnv <- getEnvironment
+    withEnvironment [("foo", "bar")] $ do
+      return ()
+    newEnv <- getEnvironment
+    newEnv `shouldMatchList` oldEnv
+  it "should allow the environment to be modified" $ do
+    withEnvironment [] $ do
+      setEnv "foo2" "bar2"
+      var <- lookupEnv "foo2"
+      var `shouldBe` Just "bar2"