diff --git a/builder/comp-builder.nix b/builder/comp-builder.nix
index 97eaa0ce59..5931ad64f9 100644
--- a/builder/comp-builder.nix
+++ b/builder/comp-builder.nix
@@ -45,7 +45,7 @@ let
 
   flatDepends =
     let
-      makePairs = map (p: rec { key="${val}"; val=p.components.library; });
+      makePairs = map (p: rec { key="${val}"; val=(p.components.library or p); });
       closure = builtins.genericClosure {
         startSet = makePairs component.depends;
         operator = {val,...}: makePairs val.config.depends;
@@ -104,7 +104,7 @@ let
     cat > $out/ghc-environment <<EOF
     package-db $out/package.conf.d
     EOF
-    ${lib.concatMapStringsSep "\n" (p: envDep "--package-db ${p.components.library}/package.conf.d" p.identifier.name) component.depends}
+    ${lib.concatMapStringsSep "\n" (p: envDep "--package-db ${p.components.library or p}/package.conf.d" p.identifier.name) component.depends}
     ${lib.concatMapStringsSep "\n" (envDep "") (lib.remove "ghc" nonReinstallablePkgs)}
 
   '' + lib.optionalString component.doExactConfig ''
@@ -294,13 +294,23 @@ stdenv.mkDerivation ({
   '';
 
   # Note: Cabal does *not* copy test executables during the `install` phase.
+  #
+  # Note 2: if a package contains multiple libs (lib + sublibs) SETUP register will generate a
+  #         folder isntead of a file for the configuration.  Therfore if the result is a folder,
+  #         we need to register each and every element of that folder.
   installPhase = ''
     runHook preInstall
     $SETUP_HS copy ${lib.concatStringsSep " " component.setupInstallFlags}
     ${lib.optionalString (haskellLib.isLibrary componentId || haskellLib.isAll componentId) ''
       $SETUP_HS register --gen-pkg-config=${name}.conf
       ${ghc.targetPrefix}ghc-pkg -v0 init $out/package.conf.d
-      ${ghc.targetPrefix}ghc-pkg -v0 --package-db ${configFiles}/package.conf.d -f $out/package.conf.d register ${name}.conf
+      if [ -d "${name}.conf" ]; then
+        for pkg in ${name}.conf/*; do
+          ${ghc.targetPrefix}ghc-pkg -v0 --package-db ${configFiles}/package.conf.d -f $out/package.conf.d register "$pkg"
+        done
+      else
+        ${ghc.targetPrefix}ghc-pkg -v0 --package-db ${configFiles}/package.conf.d -f $out/package.conf.d register ${name}.conf
+      fi
     ''}
     ${lib.optionalString (haskellLib.isTest componentId || haskellLib.isAll componentId) ''
       mkdir -p $out/${name}
diff --git a/lib/default.nix b/lib/default.nix
index 3d89d779cc..06dd919b28 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -31,7 +31,7 @@ with haskellLib;
 
   componentPrefix = {
     # Are all of these right?
-    sublibs = "sublib";
+    sublibs = "lib";
     foreignlibs = "foreignlib";
     exes = "exe";
     tests = "test";
diff --git a/modules/plan.nix b/modules/plan.nix
index 82849848ae..54fa22e686 100644
--- a/modules/plan.nix
+++ b/modules/plan.nix
@@ -53,8 +53,9 @@ with types;
 
       let m = if revision == null
               then (abort "${name} has no revision!")
-              else revision modArgs;
-      in m // { flags = lib.mapAttrs (_: lib.mkDefault) (m.flags // revArgs.flags or {}); }
+              else revision (modArgs // { hsPkgs = hsPkgs // (mapAttrs (l: _: hsPkgs.${name}.components.sublibs.${l}) (m.components.sublibs or {})); });
+      in
+        m // { flags = lib.mapAttrs (_: lib.mkDefault) (m.flags // revArgs.flags or {}); }
     ) (lib.filterAttrs (n: v: v == null || v.revision != null ) module.packages);
   };
 }
diff --git a/test/cabal-sublib/Main.hs b/test/cabal-sublib/Main.hs
new file mode 100644
index 0000000000..65ae4a05d5
--- /dev/null
+++ b/test/cabal-sublib/Main.hs
@@ -0,0 +1,4 @@
+module Main where
+
+main :: IO ()
+main = putStrLn "Hello, Haskell!"
diff --git a/test/cabal-sublib/Setup.hs b/test/cabal-sublib/Setup.hs
new file mode 100644
index 0000000000..9a994af677
--- /dev/null
+++ b/test/cabal-sublib/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/test/cabal-sublib/cabal-sublib.cabal b/test/cabal-sublib/cabal-sublib.cabal
new file mode 100644
index 0000000000..66ab36282c
--- /dev/null
+++ b/test/cabal-sublib/cabal-sublib.cabal
@@ -0,0 +1,41 @@
+cabal-version:       2.2
+-- Initial package description 'cabal-simple.cabal' generated by 'cabal
+-- init'.  For further documentation, see
+-- http://haskell.org/cabal/users-guide/
+
+name:                cabal-sublib
+version:             0.1.0.0
+-- synopsis:
+-- description:
+-- bug-reports:
+license:             MIT
+author:              Moritz Angermann
+maintainer:          moritz.angermann@iohk.io
+-- category:
+build-type:          Simple
+
+library
+  -- exposed-modules:
+  -- other-modules:
+  -- other-extensions:
+  build-depends:       base >=4.11 && <4.12
+                     , slib
+  -- hs-source-dirs:
+  default-language:    Haskell2010
+
+library slib
+  build-depends:       extra
+                     , safe
+                     , aeson
+  default-language:    Haskell2010
+
+executable cabal-sublib
+  main-is:             Main.hs
+  -- other-modules:
+  -- other-extensions:
+  build-depends:       base >=4.11 && <4.12
+                     , cabal-sublib
+                     , extra
+                     , optparse-applicative
+  -- hs-source-dirs:
+  default-language:    Haskell2010
diff --git a/test/cabal-sublib/cabal-sublib.nix b/test/cabal-sublib/cabal-sublib.nix
new file mode 100644
index 0000000000..d0af18919d
--- /dev/null
+++ b/test/cabal-sublib/cabal-sublib.nix
@@ -0,0 +1,33 @@
+{ system, compiler, flags, pkgs, hsPkgs, pkgconfPkgs, ... }:
+  {
+    flags = {};
+    package = {
+      specVersion = "2.2";
+      identifier = { name = "cabal-sublib"; version = "0.1.0.0"; };
+      license = "MIT";
+      copyright = "";
+      maintainer = "moritz.angermann@iohk.io";
+      author = "Moritz Angermann";
+      homepage = "";
+      url = "";
+      synopsis = "";
+      description = "";
+      buildType = "Simple";
+      };
+    components = {
+      "library" = { depends = [ (hsPkgs.base) (hsPkgs.slib) ]; };
+      sublibs = {
+        "slib" = { depends = [ (hsPkgs.extra) (hsPkgs.safe) (hsPkgs.aeson) ]; };
+        };
+      exes = {
+        "cabal-sublib" = {
+          depends = [
+            (hsPkgs.base)
+            (hsPkgs.cabal-sublib)
+            (hsPkgs.extra)
+            (hsPkgs.optparse-applicative)
+            ];
+          };
+        };
+      };
+    } // rec { src = (pkgs.lib).mkDefault ./.; }
diff --git a/test/cabal-sublib/default.nix b/test/cabal-sublib/default.nix
new file mode 100644
index 0000000000..8b5f1d684d
--- /dev/null
+++ b/test/cabal-sublib/default.nix
@@ -0,0 +1,67 @@
+# Test a package set
+{ stdenv, util, mkPkgSet }:
+
+with stdenv.lib;
+
+let
+  ## steps to generate local files
+  # 1. cabal-to-nix cabal-sublib.cabal > cabal-sublib.nix
+  # 2. cabal new-build
+  # 3. plan-to-nix ./dist-newstyle/cache/plan.json > plan.nix
+  pkgSet = mkPkgSet {
+    pkg-def = import ./plan.nix;
+    pkg-def-overlays = [
+      { cabal-sublib = ./cabal-sublib.nix;
+      }
+    ];
+    modules = [
+     {
+       # Package has no exposed modules which causes
+       #   haddock: No input file(s)
+       packages.cabal-sublib.doHaddock = false;
+     }
+    ];
+  };
+
+  packages = pkgSet.config.hsPkgs;
+
+in
+  stdenv.mkDerivation {
+    name = "cabal-sublib-test";
+
+    buildCommand = ''
+      exe="${packages.cabal-sublib.components.exes.cabal-sublib}/bin/cabal-sublib"
+
+      size=$(command stat --format '%s' "$exe")
+      printf "size of executable $exe is $size. \n" >& 2
+
+      # fixme: run on target platform when cross-compiled
+      printf "checking whether executable runs... " >& 2
+      $exe
+
+      printf "checking that executable is dynamically linked to system libraries... " >& 2
+    '' + optionalString stdenv.isLinux ''
+      ldd $exe | grep libpthread
+    '' + optionalString stdenv.isDarwin ''
+      otool -L $exe |grep .dylib
+    '' + ''
+
+      printf "Checking that \"all\" component has the programs... " >& 2
+      all_exe="${packages.cabal-sublib.components.all}/bin/cabal-sublib"
+      test -f "$all_exe"
+      echo "$all_exe" >& 2
+
+      touch $out
+    '';
+
+    meta.platforms = platforms.all;
+
+    passthru = {
+      # Used for debugging with nix repl
+      inherit pkgSet packages;
+
+      # Used for testing externally with nix-shell (../tests.sh).
+      # This just adds cabal-install to the existing shells.
+      test-shell = util.addCabalInstall packages.cabal-sublib.components.all;
+    };
+}
diff --git a/test/cabal-sublib/plan.nix b/test/cabal-sublib/plan.nix
new file mode 100644
index 0000000000..dead4b6b3f
--- /dev/null
+++ b/test/cabal-sublib/plan.nix
@@ -0,0 +1,111 @@
+hackage:
+  {
+    packages = {
+      "binary".revision = hackage."binary"."0.8.5.1".revisions.default;
+      "ghc-prim".revision = hackage."ghc-prim"."0.5.2.0".revisions.default;
+      "extra".revision = hackage."extra"."1.6.14".revisions.default;
+      "stm".revision = hackage."stm"."2.4.5.1".revisions.default;
+      "unix".revision = hackage."unix"."2.7.2.2".revisions.default;
+      "rts".revision = hackage."rts"."1.0".revisions.default;
+      "clock".revision = hackage."clock"."0.7.2".revisions.default;
+      "clock".flags.llvm = false;
+      "scientific".revision = hackage."scientific"."0.3.6.2".revisions.default;
+      "scientific".flags.integer-simple = false;
+      "scientific".flags.bytestring-builder = false;
+      "deepseq".revision = hackage."deepseq"."1.4.3.0".revisions.default;
+      "random".revision = hackage."random"."1.1".revisions.default;
+      "uuid-types".revision = hackage."uuid-types"."1.0.3".revisions.default;
+      "optparse-applicative".revision = hackage."optparse-applicative"."0.14.3.0".revisions.default;
+      "dlist".revision = hackage."dlist"."0.8.0.5".revisions.default;
+      "directory".revision = hackage."directory"."1.3.1.5".revisions.default;
+      "transformers-compat".revision = hackage."transformers-compat"."0.6.2".revisions.default;
+      "transformers-compat".flags.five = false;
+      "transformers-compat".flags.generic-deriving = true;
+      "transformers-compat".flags.two = false;
+      "transformers-compat".flags.five-three = true;
+      "transformers-compat".flags.mtl = true;
+      "transformers-compat".flags.four = false;
+      "transformers-compat".flags.three = false;
+      "template-haskell".revision = hackage."template-haskell"."2.13.0.0".revisions.default;
+      "vector".revision = hackage."vector"."0.12.0.2".revisions.default;
+      "vector".flags.unsafechecks = false;
+      "vector".flags.internalchecks = false;
+      "vector".flags.wall = false;
+      "vector".flags.boundschecks = true;
+      "primitive".revision = hackage."primitive"."0.6.4.0".revisions.default;
+      "time-locale-compat".revision = hackage."time-locale-compat"."0.1.1.5".revisions.default;
+      "time-locale-compat".flags.old-locale = false;
+      "safe".revision = hackage."safe"."0.3.17".revisions.default;
+      "base-compat".revision = hackage."base-compat"."0.10.5".revisions.default;
+      "ansi-terminal".revision = hackage."ansi-terminal"."0.8.2".revisions.default;
+      "ansi-terminal".flags.example = false;
+      "tagged".revision = hackage."tagged"."0.8.6".revisions.default;
+      "tagged".flags.transformers = true;
+      "tagged".flags.deepseq = true;
+      "containers".revision = hackage."containers"."0.5.11.0".revisions.default;
+      "integer-logarithms".revision = hackage."integer-logarithms"."1.0.2.2".revisions.default;
+      "integer-logarithms".flags.check-bounds = false;
+      "integer-logarithms".flags.integer-gmp = true;
+      "bytestring".revision = hackage."bytestring"."0.10.8.2".revisions.default;
+      "ansi-wl-pprint".revision = hackage."ansi-wl-pprint"."0.6.8.2".revisions.default;
+      "ansi-wl-pprint".flags.example = false;
+      "StateVar".revision = hackage."StateVar"."1.1.1.1".revisions.default;
+      "contravariant".revision = hackage."contravariant"."1.5".revisions.default;
+      "contravariant".flags.semigroups = true;
+      "contravariant".flags.tagged = true;
+      "contravariant".flags.statevar = true;
+      "contravariant".flags.safe = false;
+      "text".revision = hackage."text"."1.2.3.1".revisions.default;
+      "unordered-containers".revision = hackage."unordered-containers"."0.2.9.0".revisions.default;
+      "unordered-containers".flags.debug = false;
+      "base".revision = hackage."base"."4.11.1.0".revisions.default;
+      "time".revision = hackage."time"."1.8.0.2".revisions.default;
+      "transformers".revision = hackage."transformers"."0.5.5.0".revisions.default;
+      "hashable".revision = hackage."hashable"."1.2.7.0".revisions.default;
+      "hashable".flags.sse2 = true;
+      "hashable".flags.integer-gmp = true;
+      "hashable".flags.sse41 = false;
+      "hashable".flags.examples = false;
+      "attoparsec".revision = hackage."attoparsec"."0.13.2.2".revisions.default;
+      "attoparsec".flags.developer = false;
+      "colour".revision = hackage."colour"."2.3.4".revisions.default;
+      "filepath".revision = hackage."filepath"."1.4.2".revisions.default;
+      "process".revision = hackage."process"."1.6.3.0".revisions.default;
+      "pretty".revision = hackage."pretty"."1.1.3.6".revisions.default;
+      "aeson".revision = hackage."aeson"."1.4.2.0".revisions.default;
+      "aeson".flags.cffi = false;
+      "aeson".flags.fast = false;
+      "aeson".flags.bytestring-builder = false;
+      "aeson".flags.developer = false;
+      "ghc-boot-th".revision = hackage."ghc-boot-th"."8.4.4".revisions.default;
+      "th-abstraction".revision = hackage."th-abstraction"."0.2.10.0".revisions.default;
+      "array".revision = hackage."array"."0.5.2.0".revisions.default;
+      "integer-gmp".revision = hackage."integer-gmp"."1.0.2.0".revisions.default;
+    };
+    compiler = {
+      version = "8.4.4";
+      nix-name = "ghc844";
+      packages = {
+        "binary" = "0.8.5.1";
+        "ghc-prim" = "0.5.2.0";
+        "stm" = "2.4.5.1";
+        "unix" = "2.7.2.2";
+        "rts" = "1.0";
+        "deepseq" = "1.4.3.0";
+        "directory" = "1.3.1.5";
+        "template-haskell" = "2.13.0.0";
+        "containers" = "0.5.11.0";
+        "bytestring" = "0.10.8.2";
+        "text" = "1.2.3.1";
+        "base" = "4.11.1.0";
+        "time" = "1.8.0.2";
+        "transformers" = "0.5.5.0";
+        "filepath" = "1.4.2";
+        "process" = "1.6.3.0";
+        "pretty" = "1.1.3.6";
+        "ghc-boot-th" = "8.4.4";
+        "array" = "0.5.2.0";
+        "integer-gmp" = "1.0.2.0";
+      };
+    };
+  }
diff --git a/test/default.nix b/test/default.nix
index d9b6b256bd..9a592f1454 100644
--- a/test/default.nix
+++ b/test/default.nix
@@ -11,6 +11,7 @@ let
 
 in {
   cabal-simple = callPackage ./cabal-simple { inherit (haskell) mkPkgSet; inherit util; };
+  cabal-sublib = callPackage ./cabal-sublib { inherit (haskell) mkPkgSet; inherit util; };
   cabal-22 = callPackage ./cabal-22 { inherit (haskell) mkPkgSet; };
   with-packages = callPackage ./with-packages { inherit (haskell) mkPkgSet; inherit util; };
   builder-haddock = callPackage ./builder-haddock { inherit (haskell) mkPkgSet; };