diff --git a/haddock-library/haddock-library.cabal b/haddock-library/haddock-library.cabal
index 3b11761ebd0481fe1bf0c1edac0f3e501876d41c..9b967c00bb6f867b6412c0d8516c1ace5747f0c7 100644
--- a/haddock-library/haddock-library.cabal
+++ b/haddock-library/haddock-library.cabal
@@ -50,6 +50,12 @@ library
     Data.Attoparsec.Number
     Documentation.Haddock.Parser.Util
 
+  ghc-options: -Wall
+  if impl(ghc >= 8.0)
+    ghc-options: -Wcompat -Wnoncanonical-monad-instances -Wnoncanonical-monadfail-instances
+  else
+    build-depends: semigroups ^>= 0.18.3, fail ^>= 4.9.0.0
+
 test-suite spec
   type:             exitcode-stdio-1.0
   default-language: Haskell2010