diff --git a/.github/workflows/workflow.yml b/.github/workflows/workflow.yml
index e7b9ad49..e124e10f 100644
--- a/.github/workflows/workflow.yml
+++ b/.github/workflows/workflow.yml
@@ -49,6 +49,27 @@ jobs:
         with:
           ocaml-compiler: ${{ matrix.ocaml-version }}
 
+      - run: sudo apt install libcrypto++-dev libminiupnpc-dev libnatpmp-dev libgd-dev
+        if: matrix.os == 'ubuntu-latest'
+
+      - run: brew install cryptopp miniupnpc libnatpmp gd
+        if: matrix.os == 'macos-latest'
+
+      - run: |
+          echo "C_INCLUDE_PATH=$HOMEBREW_PREFIX/include:$C_INCLUDE_PATH" >> $GITHUB_ENV
+          echo "LIBRARY_PATH=$HOMEBREW_PREFIX/lib:$LIBRARY_PATH" >> $GITHUB_ENV
+          echo $C_INCLUDE_PATH
+          echo $LIBRARY_PATH
+        if: matrix.os == 'macos-latest'
+
+      # https://cygwin.com/packages/
+      - run: D:\\cygwin\\setup-x86_64.exe "--root" "D:\\cygwin" "--quiet-mode" "unattended" "--no-shortcuts" "--no-startmenu" "--no-desktop" "--no-admin" "--no-version-check" "--no-write-registry" "--packages" "mingw64-x86_64-gd"
+        if: matrix.os == 'windows-latest'
+
+      - run: |
+          echo $C_INCLUDE_PATH
+          echo $LIBRARY_PATH
+
       - run: opam pin add mldonkey.dev . --no-action
 
       # not needed, opam install will do it automatically
@@ -59,7 +80,7 @@ jobs:
       # https://github.com/ocaml/setup-ocaml/issues/815#issuecomment-2204838759
       # SHELLOPTS workaround for windows
       # setting SHELLOPTS via GITHUB_ENV didn't work for some reason
-      - run: opam exec -- env SHELLOPTS=igncr sh ./configure --enable-debug
+      - run: opam exec -- env SHELLOPTS=igncr sh ./configure --enable-debug --enable-upnp-natpmp
 
       - run: opam exec -- make
 
diff --git a/mldonkey.opam b/mldonkey.opam
index bbdec157..11da0452 100644
--- a/mldonkey.opam
+++ b/mldonkey.opam
@@ -9,18 +9,21 @@ Supported networks include:
  * HTTP/FTP
 MLdonkey core runs as a background daemon and provides several control
 interfaces : telnet, web, and binary protocol for third party GUIs."""
-maintainer: "ygrek@autistici.org"
+maintainer: "root@ygrek.org"
 authors: "mldonkey team"
 license: "GPL-2.0-only"
 homepage: "http://github.com/ygrek/mldonkey"
 dev-repo: "git+https://github.com/ygrek/mldonkey.git"
 bug-reports: "https://github.com/ygrek/mldonkey/issues"
+# mldonkey has many optional components (most of which depend on system libraries),
+# this set of dependencies here represents one arbitrary selection
 depends: [
   "ocaml" {>= "4.03.0"}
   "camlp4"
+  "conf-gd" {optional} # graphical stats
   "conf-m4"
   "conf-zlib"
-  "num"
+  "num" # technically optional, enables bittorrent
 ]
 build: [
   ["./configure" "--enable-debug" "--prefix" prefix]