diff --git a/packages/genodelabs/default.nix b/packages/genodelabs/default.nix
index 459d73b..b21a1d5 100644
--- a/packages/genodelabs/default.nix
+++ b/packages/genodelabs/default.nix
@@ -40,7 +40,16 @@ let
       substituteInPlace tool/check_abi \
         --replace "exec nm" "exec ${toolPrefix}nm"
     '';
-    dontBuild = true;
+
+    buildPhase = ''
+      echo { >> ports.nix
+      find repos/*/ports -name '*.hash' | while read hashFile
+      do
+        echo "  $(basename --suffix=.hash $hashFile) = \"$(cut -c -6 $hashFile)\";" >> ports.nix
+      done
+      echo } >> ports.nix
+    '';
+
     installPhase = "cp -a . $out";
   };
 
@@ -53,12 +62,13 @@ let
     { hash ? "sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="
     , patches ? [ ], ... }@args:
     let havePatches = patches != [ ];
+      version = builtins.getAttr name (import "${genodeSources}/ports.nix");
     in stdenvNoCC.mkDerivation (args // {
+      name = name + "-port-" + version;
+      inherit version patches;
+      preferLocalBuild = true;
       outputHashMode = "recursive";
       outputHash = hash;
-      pname = name;
-      inherit (genodeSources) version;
-      inherit patches;
 
       GIT_SSL_CAINFO = "${cacert}/etc/ssl/certs/ca-bundle.crt";
       VERBOSE = "";
@@ -83,7 +93,7 @@ let
           export CONTRIB_DIR=$NIX_BUILD_TOP/contrib
           export GENODE_DIR=${if havePatches then "$(pwd)" else genodeSources}
           mkdir $CONTRIB_DIR
-          $GENODE_DIR/tool/ports/prepare_port $pname CHECK_HASH=no
+          $GENODE_DIR/tool/ports/prepare_port ${name} CHECK_HASH=no
           runHook postBuild
         '';
 
@@ -96,6 +106,7 @@ let
           find $CONTRIB_DIR/* -name .svn -exec rm -rf {} \; || true
           find $CONTRIB_DIR/* -name '*.t?z' -exec rm -rf {} \; || true
           find $CONTRIB_DIR/* -name '*.tar.*' -exec rm -rf {} \; || true
+          find $CONTRIB_DIR/* -name '*.zip' -exec rm -rf {} \; || true
 
           mkdir $out
           cp -a $CONTRIB_DIR/* $out/
diff --git a/packages/genodelabs/openssl.patch b/packages/genodelabs/openssl.patch
deleted file mode 100644
index 73ebb95..0000000
--- a/packages/genodelabs/openssl.patch
+++ /dev/null
@@ -1,13 +0,0 @@
-diff --git a/repos/libports/ports/openssl.port b/repos/libports/ports/openssl.port
-index 7cdb34b07a..081a6a9a54 100644
---- a/repos/libports/ports/openssl.port
-+++ b/repos/libports/ports/openssl.port
-@@ -2,7 +2,7 @@ LICENSE   := OpenSSL
- VERSION   := 1.0.2q
- DOWNLOADS := openssl.archive
- 
--URL(openssl) := https://www.openssl.org/source/openssl-$(VERSION).tar.gz
-+URL(openssl) := https://www.openssl.org/source/old/1.0.2/openssl-1.0.2q.tar.gz
- SHA(openssl) := 5744cfcbcec2b1b48629f7354203bc1e5e9b5466998bbccc5b5fcde3b18eb684
- DIR(openssl) := src/lib/openssl
- 
diff --git a/packages/genodelabs/ports.nix b/packages/genodelabs/ports.nix
index 768be6a..09c78d4 100644
--- a/packages/genodelabs/ports.nix
+++ b/packages/genodelabs/ports.nix
@@ -1,43 +1,38 @@
-# ports are superficially similar to Nix, but inferior in every way
 { buildPackages }:
 with buildPackages; {
   dde_bsd.hash = "sha256-2ilZs6JkcQAvU/sQYnHunGtGRZDt7qLTpKZxQxSOf2I=";
-  dde_ipxe.hash = "sha256-uK110Cr01D6I2Fo0ZNP5U7rheseuH7LsghSPdFaGU3k=";
-  dde_linux.hash = "sha256-3G5Mprv9ZBNhDJRuVF6Nrkp3KbFaN10IKFq0OdyAY9M=";
+  dde_ipxe.hash = "sha256-7J8Loy3e79LAAARQgNixN4NT8lUktgkvl3tZQK+OlMM=";
+  dde_linux.hash = "sha256-ePNLGyr9A9udzuV5RPaQYjCDc/yns89Yp3h7vQkeBg4=";
   dde_rump = {
     hash = "sha256-Wr5otGkWEa+5xImsFHQzwap5LckNEbyWA/7xbNcOreI=";
     nativeBuildInputs = [ subversion ];
     patches = [ ./svn-trust-server-cert.patch ];
   };
-  expat.hash = "sha256-6Kz8qHmSg9/r+o3UJX8ZyB5aDjmfrbsUW/TppbB16jk=";
+  expat.hash = "sha256-wkqqtYTctVLYZoYbFP1iWL0Xx/mMec40gVxk9amSywU=";
   jitterentropy.hash = "sha256-6KS732GxtUMz0xPYKtshdn039DgdJq11vTDQesZn4Ds=";
-  jpeg.hash = "sha256-fiRwzwEDVd1Xgd+k4WOez8AfR4brsBg7g0D9+9VJZr4=";
+  jpeg.hash = "sha256-NRcaGchA0DH2g5OkWBOiFK5co6lMpAo1ELqtxRUR3do=";
   libc = {
-    hash = "sha256-WecWj8rLBzG4hipOfPShhootOuBQW4sA4SSzFPMTbrw=";
+    hash = "sha256-U9DdP0yZIDptgFRNv3QCxWoC4P3N6bqVr4YZi730Fec=";
     nativeBuildInputs = [ buildPackages.gcc ];
   };
-  libiconv.hash = "sha256-H1BPWDmQ4s0zLnCitg+kz2yNeTU7+S7/w58SqmvHWGQ=";
-  libpng.hash = "sha256-N69Q7ciQuW4sFl5k5XIe7rdkQvYZ3qfo6FlvgDgDGJo=";
+  libiconv.hash = "sha256-HR19++jiYBnCO03EsfryUmVzukS874pE658gYivnMnI=";
+  libpng.hash = "sha256-BZI9UcKjP8u1/x8iroqqOyS1VEUZJLuE560W7J5PRGo=";
   libssh.hash = "sha256-Z/1YdhISh2kqBjWiTOLkS+usoeeekJvAuYrVUgpxnQM=";
-  lwip.hash = "sha256-mB7RI9ITvS5IDawQS4pXBcDQDQhtXEk3w0Deis+SzLQ=";
-  lz4.hash = "sha256-IFfj+D5l+BE6JnuN0+doIAvTzXz5SHCQ+EF2m75UK08=";
+  lwip.hash = "sha256-Zsz+zGFRz9oacWCOGtZrCnXjJM1fT+iwW/RxR4kUX2I=";
+  lz4.hash = "sha256-BBo/ZoX0om5OdN148pFUL1JnD5iL2f9dq9x0zsWjyKI=";
   mesa = {
-    hash = "sha256-szIyFAIkL14xBMdszkox00y2uwGwjHDUyQ+5bhljiJ8=";
+    hash = "sha256-5SHU4m3kMmi6Nfj4SBq2tO3mzsIBrRPz64dexjV4pYA=";
     nativeBuildInputs = [ python ];
   };
-  mupdf.hash = "sha256-+Q4IwYGLynoud2IEsKGfZQjpPRV6wFv5iI/ReAKBZcM=";
-  openssl = {
-    hash = "sha256-F0olTWYUwD//eJZ14ibN/IvbFXw3WQUZ/6cPI3lsxZI=";
-    patches = [ ./openssl.patch ];
-  };
+  mupdf.hash = "sha256-Q9uZDIguJDXPOWrQutwJvoQI8ds1MmhMH17GpGAl+Pk=";
+  openssl.hash = "sha256-K/flYHGOabnRplSLk13qej2prX5oILyHknNgRHlNtIY=";
   qemu-usb.hash = "sha256-F4ZXeH5sx3FOcD42zFOxKFMsqGookKdav1NJ7YgVw98=";
   stb.hash = "sha256-9LSH1i8jcEvjRAmTvgtK+Axy9hO7uiSzmSgBvs0zkTc=";
-  stdcxx.hash = "sha256-U5/+yUBXQ+rKmy6hP7OomIU4g2KvSn2qTltQFzNz9Wo=";
+  stdcxx.hash = "sha256-3pGfDRE+MMgM/ARmgktyIMnhJ/poe6NOfueBwehHDXQ=";
   virtualbox5 = {
-    hash = "sha256-2QJMXsr5P+Uu/xz6M+F93JxBznVdE7ZsoZKC2o/Xycw=";
+    hash = "sha256-lMcZYL60t+4zOPog8idB8Hd9sFoa1f83caoN9Rw15WU=";
     nativeBuildInputs = [ iasl libxslt unzip yasm ];
-    patches = [ ./vbox5-iasl.patch ];
   };
   x86emu.hash = "sha256-QY6OL+cDVjQ67JItP1rS4ufPRGZf43AZtWxwza/0q0w=";
-  zlib.hash = "sha256-+jl8Q3b+fw6P3aNDfLi8lohBJNaoapEld5BcE0GGTWg=";
+  zlib.hash = "sha256-lq1VaD9huqW7pwrAbujoPosDK43xMKS++5HQstgMfa0=";
 }