diff --git a/servant-client/test/Servant/ClientSpec.hs b/servant-client/test/Servant/ClientSpec.hs
index 4ea5cacf..344f42ef 100644
--- a/servant-client/test/Servant/ClientSpec.hs
+++ b/servant-client/test/Servant/ClientSpec.hs
@@ -6,8 +6,10 @@
 {-# LANGUAGE FunctionalDependencies #-}
 {-# LANGUAGE GADTs                  #-}
 {-# LANGUAGE MultiParamTypeClasses  #-}
-{-# LANGUAGE OverloadedStrings      #-}
+#if !MIN_VERSION_base(4,8,0)
 {-# LANGUAGE OverlappingInstances   #-}
+#endif
+{-# LANGUAGE OverloadedStrings      #-}
 {-# LANGUAGE PolyKinds              #-}
 {-# LANGUAGE RecordWildCards        #-}
 {-# LANGUAGE StandaloneDeriving     #-}
@@ -347,17 +349,33 @@ pathGen = fmap NonEmpty path
 class GetNth (n :: Nat) a b | n a -> b where
     getNth :: Proxy n -> a -> b
 
-instance GetNth 0 (x :<|> y) x where
-    getNth _ (x :<|> _) = x
+instance 
+#if MIN_VERSION_base(4,8,0)
+         {-# OVERLAPPING #-}
+#endif
+  GetNth 0 (x :<|> y) x where
+      getNth _ (x :<|> _) = x
 
-instance (GetNth (n - 1) x y) => GetNth n (a :<|> x) y where
-    getNth _ (_ :<|> x) = getNth (Proxy :: Proxy (n - 1)) x
+instance 
+#if MIN_VERSION_base(4,8,0)
+         {-# OVERLAPPING #-}
+#endif
+  (GetNth (n - 1) x y) => GetNth n (a :<|> x) y where
+      getNth _ (_ :<|> x) = getNth (Proxy :: Proxy (n - 1)) x
 
 class GetLast a b | a -> b where
     getLast :: a -> b
 
-instance (GetLast b c) => GetLast (a :<|> b) c where
-    getLast (_ :<|> b) = getLast b
+instance 
+#if MIN_VERSION_base(4,8,0)
+         {-# OVERLAPPING #-}
+#endif
+  (GetLast b c) => GetLast (a :<|> b) c where
+      getLast (_ :<|> b) = getLast b
 
-instance GetLast a a where
-    getLast a = a
+instance 
+#if MIN_VERSION_base(4,8,0)
+         {-# OVERLAPPING #-}
+#endif
+  GetLast a a where
+      getLast a = a