diff --git a/test/Rollbar/QuickCheck.hs b/test/Rollbar/QuickCheck.hs
--- a/test/Rollbar/QuickCheck.hs
+++ b/test/Rollbar/QuickCheck.hs
@@ -17,6 +17,7 @@
 import Rollbar.Item
 
 import Test.QuickCheck
+import Test.QuickCheck.Modifiers (getASCIIString)
 
 import qualified Data.ByteString.Char8 as BSC8
 import qualified Data.Text             as T
@@ -25,12 +26,12 @@
     arbitrary = Item <$> arbitrary <*> arbitrary
 
 instance Arbitrary AccessToken where
-    arbitrary = AccessToken . T.pack <$> arbitrary
+    arbitrary = AccessToken . T.pack . getASCIIString <$> arbitrary
 
 instance Arbitrary a => Arbitrary (Data a '["Authorization"]) where
     arbitrary = do
-        env <- Environment . T.pack <$> arbitrary
-        message <- fmap (MessageBody . T.pack) <$> arbitrary
+        env <- Environment . T.pack . getASCIIString <$> arbitrary
+        message <- fmap (MessageBody . T.pack . getASCIIString) <$> arbitrary
         payload <- arbitrary
         elements $ (\f -> f env message payload) <$> datas
 
diff --git a/wai-middleware-rollbar.cabal b/wai-middleware-rollbar.cabal
--- a/wai-middleware-rollbar.cabal
+++ b/wai-middleware-rollbar.cabal
@@ -1,5 +1,5 @@
 name:                wai-middleware-rollbar
-version:             0.8.1
+version:             0.8.2
 synopsis:            Middleware that communicates to Rollbar.
 description:         Middleware that communicates to Rollbar.
 homepage:            https://github.com/joneshf/wai-middleware-rollbar#readme
@@ -62,7 +62,7 @@
                      , Rollbar.Item.Request.Test
                      , Rollbar.QuickCheck
   build-depends:       base
-                     , QuickCheck >= 2.9 && < 2.11
+                     , QuickCheck >= 2.9 && < 2.12
                      , aeson
                      , bytestring
                      , case-insensitive