diff --git a/haddock-api/haddock-api.cabal b/haddock-api/haddock-api.cabal
index 2389540dd6161df82eb9905de5604d925b453834..f4b2fa04bd1ef3466af61ece78b8212002f44215 100644
--- a/haddock-api/haddock-api.cabal
+++ b/haddock-api/haddock-api.cabal
@@ -68,6 +68,7 @@ library
   ghc-options: -funbox-strict-fields -O2
                -Wall
                -Wcompat
+               -Wcompat-unqualified-imports
                -Widentities
                -Wredundant-constraints
                -Wnoncanonical-monad-instances