diff --git a/cabal-install/Distribution/Client/PlanIndex.hs b/cabal-install/Distribution/Client/PlanIndex.hs
index b4f96e305079c3f13ba33d0c262293f2c2fa6174..ae05b1d55698f4bb0f06b978601ceeafd3f7e5e9 100644
--- a/cabal-install/Distribution/Client/PlanIndex.hs
+++ b/cabal-install/Distribution/Client/PlanIndex.hs
@@ -104,7 +104,7 @@ fakeLookupInstalledPackageId fakeMap index pkg =
 --
 -- Returns such packages along with the dependencies that they're missing.
 --
-brokenPackages :: (HasInstalledPackageId pkg, PackageFixedDeps pkg)
+brokenPackages :: (PackageFixedDeps pkg)
                => FakeMap
                -> PackageIndex pkg
                -> [(pkg, [InstalledPackageId])]