diff --git a/src/Servant/QuickCheck/Internal/HasGenRequest.hs b/src/Servant/QuickCheck/Internal/HasGenRequest.hs
index d71ac93..010842f 100644
--- a/src/Servant/QuickCheck/Internal/HasGenRequest.hs
+++ b/src/Servant/QuickCheck/Internal/HasGenRequest.hs
@@ -15,9 +15,8 @@ import Servant
 import Servant.API.ContentTypes (AllMimeRender (..))
 import Servant.Client           (BaseUrl (..), Scheme (..))
 import Test.QuickCheck          (Arbitrary (..), Gen, elements, oneof)
-#if MIN_VERSION_servant(0,8,0)
+
 import qualified Data.ByteString as BS
-#endif
 
 
 class HasGenRequest a where
@@ -91,9 +90,10 @@ instance (KnownSymbol x, Arbitrary c, ToHttpApiData c, HasGenRequest b)
     genRequest _ = do
       new' <- new
       old' <- old
-      return $ \burl -> let r = old' burl in r {
-          queryString = queryString r
-                     <> param <> "=" <> cs (toQueryParam new') }
+      return $ \burl -> let r = old' burl
+                            newExpr = param <> "=" <> cs (toQueryParam new')
+                            qs = queryString r in r {
+          queryString = if BS.null qs then newExpr else newExpr <> "&" <> qs }
       where
         old = genRequest (Proxy :: Proxy b)
         param = cs $ symbolVal (Proxy :: Proxy x)
@@ -118,8 +118,9 @@ instance (KnownSymbol x, HasGenRequest b)
     => HasGenRequest (QueryFlag x :> b) where
     genRequest _ = do
       old' <- old
-      return $ \burl -> let r = old' burl in r {
-          queryString = queryString r <> param <> "=" }
+      return $ \burl -> let r = old' burl
+                            qs = queryString r in r {
+          queryString = if BS.null qs then param else param <> "&" <> qs }
       where
         old = genRequest (Proxy :: Proxy b)
         param = cs $ symbolVal (Proxy :: Proxy x)
diff --git a/test/Servant/QuickCheck/InternalSpec.hs b/test/Servant/QuickCheck/InternalSpec.hs
index 54c5159..0e6c053 100644
--- a/test/Servant/QuickCheck/InternalSpec.hs
+++ b/test/Servant/QuickCheck/InternalSpec.hs
@@ -4,12 +4,16 @@ module Servant.QuickCheck.InternalSpec (spec) where
 import           Control.Concurrent.MVar (newMVar, readMVar, swapMVar)
 import           Control.Monad.IO.Class  (liftIO)
 import qualified Data.ByteString         as BS
+import qualified Data.ByteString.Char8   as C
 import           Prelude.Compat
 import           Servant
 import           Test.Hspec              (Spec, context, describe, it, shouldBe,
                                           shouldContain)
 import           Test.Hspec.Core.Spec    (Arg, Example, Result (..),
                                           defaultParams, evaluateExample)
+import           Test.QuickCheck.Gen     (unGen)
+import           Test.QuickCheck.Random  (mkQCGen)
+import           Network.HTTP.Client     (queryString)
 
 #if MIN_VERSION_servant(0,8,0)
 import Servant.API.Internal.Test.ComprehensiveAPI (comprehensiveAPIWithoutRaw)
@@ -28,6 +32,8 @@ spec = do
   isComprehensiveSpec
   onlyJsonObjectSpec
   notLongerThanSpec
+  queryParamsSpec
+  queryFlagsSpec
 
 serversEqualSpec :: Spec
 serversEqualSpec = describe "serversEqual" $ do
@@ -107,6 +113,27 @@ isComprehensiveSpec = describe "HasGenRequest" $ do
     let _g = genRequest comprehensiveAPIWithoutRaw
     True `shouldBe` True -- This is a type-level check
 
+queryParamsSpec :: Spec
+queryParamsSpec = describe "QueryParams" $ do
+
+  it "reduce to an HTTP query string correctly" $ do
+    let rng = mkQCGen 0
+        burl = BaseUrl Http "localhost" 80 ""
+        gen = genRequest paramsAPI
+        req = (unGen gen rng 0) burl
+        qs = C.unpack $ queryString req
+    qs `shouldBe` "one=_&two=_"
+
+queryFlagsSpec :: Spec
+queryFlagsSpec = describe "QueryFlags" $ do
+
+  it "reduce to an HTTP query string correctly" $ do
+    let rng = mkQCGen 0
+        burl = BaseUrl Http "localhost" 80 ""
+        gen = genRequest flagsAPI
+        req = (unGen gen rng 0) burl
+        qs = C.unpack $ queryString req
+    qs `shouldBe` "one&two"
 
 ------------------------------------------------------------------------------
 -- APIs
@@ -119,6 +146,17 @@ type API = ReqBody '[JSON] String :> Post '[JSON] String
 api :: Proxy API
 api = Proxy
 
+type ParamsAPI = QueryParam "one" () :> QueryParam "two" () :> Get '[JSON] ()
+
+paramsAPI :: Proxy ParamsAPI
+paramsAPI = Proxy
+
+type FlagsAPI = QueryFlag "one" :> QueryFlag "two" :> Get '[JSON] ()
+
+flagsAPI :: Proxy FlagsAPI
+flagsAPI = Proxy
+
+
 server :: IO (Server API)
 server = do
     mvar <- newMVar ""