diff --git a/flake.lock b/flake.lock
index abca65e..f8ba7a1 100644
--- a/flake.lock
+++ b/flake.lock
@@ -5,11 +5,11 @@
         "nixpkgs": "nixpkgs"
       },
       "locked": {
-        "lastModified": 1614366386,
-        "narHash": "sha256-zs91mU2gQUzvcShKckdWfBIV3eTVmjZRZn3j+z8p7eE=",
+        "lastModified": 1615634419,
+        "narHash": "sha256-VSPhQ2wvwrPbnfxPGsXQe3lTEsTOk9mUjfD/WVDPskM=",
         "owner": "nix-community",
         "repo": "flake-nimble",
-        "rev": "5f7ef9476c394985fee98b71631641970d7ffb07",
+        "rev": "79d42ec0ba0349a967b38db70ae2e3e2f6d9c3e2",
         "type": "github"
       },
       "original": {
@@ -33,11 +33,11 @@
     },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1613672748,
-        "narHash": "sha256-8f/GGmO8zWSQj2lVjoDyQDURk6Nx9lY0VC7MwkE/Y8U=",
+        "lastModified": 1615205753,
+        "narHash": "sha256-XIYZwHzrTgRkwQ8Dl+yoFbkOHxPinWlp11X8m4IOxHQ=",
         "owner": "ehmry",
         "repo": "nixpkgs",
-        "rev": "5a18ecda0f9f79e7d1de49512ae74c01ddbb4909",
+        "rev": "c5de11a19e5c30fce1b1abf5e3e71489e2666f5e",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index 258d979..a1f2421 100644
--- a/flake.nix
+++ b/flake.nix
@@ -168,7 +168,7 @@
           if localSystem == crossSystem then
             f {
               inherit system;
-              overlays = [ self.overlay nimble.overlay ];
+              overlays = [ self.overlay ];
             }
           else
             f {
@@ -178,7 +178,7 @@
                 useLLVM = true;
               };
               config.allowUnsupportedSystem = true;
-              overlays = [ self.overlay nimble.overlay ];
+              overlays = [ self.overlay ];
             });
 
       packages =
diff --git a/overlay/default.nix b/overlay/default.nix
index 98adaa5..0b31505 100644
--- a/overlay/default.nix
+++ b/overlay/default.nix
@@ -172,20 +172,25 @@ in nullPkgs // {
     # Stay clear of upstream on this one.
     addPatchesHost [ ./ncurses/genode.patch ] ncurses;
 
-  nim =
-    # Nim is configured to build Genode with GCC.
-    overrideAttrsTarget (attrs: {
-      postInstall = ''
-        sed \
-          -e '/cc = gcc/d' \
-          -i $out/etc/nim/nim.cfg
-      '';
-    }) prev.nim;
-
-  nim-unwrapped = addPatchesTarget [
-    ./nim/genode.patch
+  nim-unwrapped =
     # Fixes to the compiler and standard libary.
-  ] prev.nim-unwrapped;
+    prev.nim-unwrapped.overrideAttrs
+    (attrs: { patches = attrs.patches ++ [ ./nim/genode.patch ]; });
+
+  nimblePackages =
+    # Packages from the Nimble flake with adjustments.
+    let pkgs' = flake.inputs.nimble.overlay (final // pkgs') final;
+    in pkgs'.nimblePackages.extend (final: prev: {
+
+      genode = prev.genode.overrideAttrs (attrs: {
+        src = fetchgit {
+          inherit (attrs.src) url;
+          rev = "27ab40d6cb8870ae306be5d09b7513db14bf4343";
+          sha256 = "1hzvyk6djnb65sl2x0sxc57vwaghvzyynp0pxvmnfbj08vp99v0m";
+        };
+      });
+
+    });
 
   openssl =
     overrideHost { static = true; } # shared library comes out stupid big
diff --git a/overlay/tup/setup-hook.sh b/overlay/tup/setup-hook.sh
deleted file mode 100644
index 5bf64ae..0000000
--- a/overlay/tup/setup-hook.sh
+++ /dev/null
@@ -1,44 +0,0 @@
-#!/bin/sh
-
-tupConfigurePhase() {
-	runHook preConfigure
-
-	echo -n CONFIG_TUP_ARCH= >> tup.config
-	case "$system" in
-	"i686-*")      echo i386 >> tup.config;;
-	"x86_64-*")    echo x86_64 >> tup.config;;
-	"powerpc-*")   echo powerpc >> tup.config;;
-	"powerpc64-*") echo powerpc64 >> tup.config;;
-	"ia64-*")      echo ia64 >> tup.config;;
-	"alpha-*")     echo alpha >> tup.config;;
-	"sparc-*")     echo sparc >> tup.config;;
-	"aarch64-*")   echo arm64 >> tup.config;;
-	"arm*")        echo arm >> tup.config;;
-	esac
-
-	echo "${tupConfig-}" >> tup.config
-
-	tup init
-	tup generate tupBuild.sh
-
-	runHook postConfigure
-}
-
-if [ -z "${dontUseTupConfigure-}" -a -z "${configurePhase-}" ]; then
-    configurePhase=tupConfigurePhase
-fi
-
-
-tupBuildPhase() {
-	runHook preBuild
-
-	pushd .
-	. tupBuild.sh
-	popd
-
-	runHook postBuild
-}
-
-if [ -z "${dontUseTupBuild-}" -a -z "${buildPhase-}" ]; then
-    buildPhase=tupBuildPhase
-fi