diff --git a/exes/Main.hs b/exes/Main.hs
index 2cef39fd..2e4723f1 100644
--- a/exes/Main.hs
+++ b/exes/Main.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP #-}
+{-# LANGUAGE PatternSynonyms #-}
 
 {-# OPTIONS_GHC -fno-warn-incomplete-uni-patterns #-}
 
@@ -41,7 +42,7 @@ import Network.URI
          ( URI(..), URIAuth(..), parseAbsoluteURI )
 import Distribution.Simple.Command
 import Distribution.Simple.Setup
-         ( Flag(..), fromFlag, fromFlagOrDefault, flagToList, flagToMaybe )
+         ( Flag, pattern Flag, pattern NoFlag, fromFlag, fromFlagOrDefault, flagToList, flagToMaybe )
 import Data.Maybe
          ( isNothing )
 import Data.List
diff --git a/hackage-server.cabal b/hackage-server.cabal
index ed28e49c..8020a9c4 100644
--- a/hackage-server.cabal
+++ b/hackage-server.cabal
@@ -146,8 +146,8 @@ common defaults
   -- other dependencies shared by most components
   build-depends:
     , aeson                  >= 2.1.0.0 && < 2.3
-    , Cabal                  >= 3.14.2.0 && < 3.16
-    , Cabal-syntax           >= 3.14.2.0 && < 3.16
+    , Cabal                  >= 3.14.2.0 && < 3.18
+    , Cabal-syntax           >= 3.14.2.0 && < 3.18
         -- Cabal-syntax needs to be bound to constrain hackage-security
         -- see https://github.com/haskell/hackage-server/issues/1130
     , fail                  ^>= 4.9.0
diff --git a/src/Distribution/Server/Framework/Instances.hs b/src/Distribution/Server/Framework/Instances.hs
index 2e12816b..5166371c 100644
--- a/src/Distribution/Server/Framework/Instances.hs
+++ b/src/Distribution/Server/Framework/Instances.hs
@@ -250,7 +250,9 @@ instance SafeCopy CompilerFlavor where
     putCopy JHC               = contain $ putWord8 7
     putCopy LHC               = contain $ putWord8 8
     putCopy UHC               = contain $ putWord8 9
+#if !MIN_VERSION_Cabal_syntax(3,16,0)
     putCopy (HaskellSuite s)  = contain $ putWord8 10 >> safePut s
+#endif
     putCopy GHCJS             = contain $ putWord8 11
     putCopy Eta               = contain $ putWord8 12
 #if MIN_VERSION_Cabal_syntax(3,12,1)
@@ -270,7 +272,9 @@ instance SafeCopy CompilerFlavor where
         7  -> return JHC
         8  -> return LHC
         9  -> return UHC
+#if !MIN_VERSION_Cabal_syntax(3,16,0)
         10 -> return HaskellSuite <*> safeGet
+#endif
         11 -> return GHCJS
         12 -> return Eta
 #if MIN_VERSION_Cabal_syntax(3,12,1)
@@ -411,7 +415,9 @@ instance Arbitrary CompilerFlavor where
     , pure JHC
     , pure LHC
     , pure UHC
+#if !MIN_VERSION_Cabal_syntax(3,16,0)
     , pure HaskellSuite <*> vectorOf 3 (choose ('A', 'Z'))
+#endif
     , pure GHCJS
     , pure Eta
 #if MIN_VERSION_Cabal_syntax(3,12,1)