diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index f386bdda7..4cb80a2fe 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -12,6 +12,20 @@ jobs:
     - uses: actions/checkout@v1
     - name: Install dependencies
       run: brew install gtk+3 gtkmm3 gtk-mac-integration adwaita-icon-theme libsigc++ little-cms2 libiptcdata fftw lensfun llvm expat pkgconfig libomp
+    - name: patch libiconv
+      run: |
+        mkdir libiconv && cd libiconv
+        wget https://ftp.gnu.org/pub/gnu/libiconv/libiconv-1.16.tar.gz
+        tar xf libiconv-1.16.tar.gz
+        cd libiconv-1.16
+        patch -p1 < "${GITHUB_WORKSPACE}/tools/osx/libiconv_1.16_rt.patch"
+        mkdir build && cd build
+        destDir="$(pwd)"
+        ../configure --prefix=/opt/local --disable-static 'CFLAGS=-arch x86_64 -mmacosx-version-min=10.9' 'LDFLAGS=-arch x86_64 -mmacosx-version-min=10.9' CXXFLAGS="-arch x86_64 -mmacosx-version-min=10.9"
+        make --jobs 2
+        make DESTDIR="${destDir}" install
+        sudo cp opt/local/lib/libiconv.2.dylib /usr/lib/libiconv.2.dylib
+        cd -
     - name: cmake
       env:
         CMAKE_CXX_STANDARD: 11
@@ -39,7 +53,7 @@ jobs:
           -DOpenMP_C_FLAGS="${C_FLAGS}" \
           -DOpenMP_CXX_FLAGS="${C_FLAGS}" \
           ..
-        make --jobs 8
+        make --jobs 2
         make install
         sudo make macosx_bundle
         ARTIFACT=$(ls | grep RawTherapee*.zip)