diff --git a/Cabal/src/Distribution/Simple/Build/Macros.hs b/Cabal/src/Distribution/Simple/Build/Macros.hs
index 3dbce8616fc..f3c51d71c96 100644
--- a/Cabal/src/Distribution/Simple/Build/Macros.hs
+++ b/Cabal/src/Distribution/Simple/Build/Macros.hs
@@ -58,7 +58,7 @@ generateCabalMacrosHeader pkg_descr lbi clbi =
           , let (major1, major2, minor) = majorMinor ver
           ]
       , Z.zPackageKey = case clbi of
-          LibComponentLocalBuildInfo{} -> componentCompatPackageKey clbi
+          LibComponentLocalBuildInfo{componentCompatPackageKey = compatPackageKey} -> compatPackageKey
           _ -> ""
       , Z.zComponentId = prettyShow (componentComponentId clbi)
       , Z.zPackageVersion = pkgVersion (package pkg_descr)
diff --git a/Cabal/src/Distribution/Simple/Register.hs b/Cabal/src/Distribution/Simple/Register.hs
index 90704e68269..76e7528a6c2 100644
--- a/Cabal/src/Distribution/Simple/Register.hs
+++ b/Cabal/src/Distribution/Simple/Register.hs
@@ -497,9 +497,9 @@ generalInstalledPackageInfo adjustRelIncDirs pkg abi_hash lib lbi clbi installDi
     { IPI.sourcePackageId = packageId pkg
     , IPI.installedUnitId = componentUnitId clbi
     , IPI.installedComponentId_ = componentComponentId clbi
-    , IPI.instantiatedWith = componentInstantiatedWith clbi
+    , IPI.instantiatedWith = expectLibraryComponent (maybeComponentInstantiatedWith clbi)
     , IPI.sourceLibName = libName lib
-    , IPI.compatPackageKey = componentCompatPackageKey clbi
+    , IPI.compatPackageKey = expectLibraryComponent (maybeComponentCompatPackageKey clbi)
     , -- If GHC >= 8.4 we register with SDPX, otherwise with legacy license
       IPI.license =
         if ghc84
@@ -518,7 +518,7 @@ generalInstalledPackageInfo adjustRelIncDirs pkg abi_hash lib lbi clbi installDi
     , IPI.indefinite = componentIsIndefinite clbi
     , IPI.exposed = libExposed lib
     , IPI.exposedModules =
-        componentExposedModules clbi
+        expectLibraryComponent (maybeComponentExposedModules clbi)
           -- add virtual modules into the list of exposed modules for the
           -- package database as well.
           ++ map (\name -> IPI.ExposedModule name Nothing) (virtualModules bi)
@@ -601,6 +601,8 @@ generalInstalledPackageInfo adjustRelIncDirs pkg abi_hash lib lbi clbi installDi
           )
       | otherwise =
           (libdir installDirs : dynlibdir installDirs : extraLibDirs', [])
+    expectLibraryComponent (Just attribute) = attribute
+    expectLibraryComponent Nothing = (error "generalInstalledPackageInfo: Expected a library component, got something else.")
 
 -- the compiler doesn't understand the dynamic-library-dirs field so we
 -- add the dyn directory to the "normal" list in the library-dirs field
diff --git a/Cabal/src/Distribution/Types/ComponentLocalBuildInfo.hs b/Cabal/src/Distribution/Types/ComponentLocalBuildInfo.hs
index 0728656620e..9e63cae52ea 100644
--- a/Cabal/src/Distribution/Types/ComponentLocalBuildInfo.hs
+++ b/Cabal/src/Distribution/Types/ComponentLocalBuildInfo.hs
@@ -6,6 +6,8 @@ module Distribution.Types.ComponentLocalBuildInfo
   ( ComponentLocalBuildInfo (..)
   , componentIsIndefinite
   , maybeComponentInstantiatedWith
+  , maybeComponentCompatPackageKey
+  , maybeComponentExposedModules
   ) where
 
 import Distribution.Compat.Prelude
@@ -126,3 +128,13 @@ maybeComponentInstantiatedWith :: ComponentLocalBuildInfo -> Maybe [(ModuleName,
 maybeComponentInstantiatedWith
   LibComponentLocalBuildInfo{componentInstantiatedWith = insts} = Just insts
 maybeComponentInstantiatedWith _ = Nothing
+
+maybeComponentCompatPackageKey :: ComponentLocalBuildInfo -> Maybe String
+maybeComponentCompatPackageKey
+  LibComponentLocalBuildInfo{componentCompatPackageKey = key} = Just key
+maybeComponentCompatPackageKey _ = Nothing
+
+maybeComponentExposedModules :: ComponentLocalBuildInfo -> Maybe [Installed.ExposedModule]
+maybeComponentExposedModules
+  LibComponentLocalBuildInfo{componentExposedModules = exposed} = Just exposed
+maybeComponentExposedModules _ = Nothing