diff --git a/.github/travis_build.sh b/.github/travis_build.sh
index c8dec1a6..75a51165 100644
--- a/.github/travis_build.sh
+++ b/.github/travis_build.sh
@@ -2,7 +2,6 @@
 ## vim:set ts=4 sw=4 et:
 set -e; set -o pipefail
 
-# Support for Travis CI -- https://travis-ci.org/upx/upx/builds
 # Copyright (C) Markus Franz Xaver Johannes Oberhumer
 
 if [[ $TRAVIS_OS_NAME == osx ]]; then
diff --git a/.github/travis_deploy.sh b/.github/travis_deploy.sh
index 5d828d3c..62e59dda 100644
--- a/.github/travis_deploy.sh
+++ b/.github/travis_deploy.sh
@@ -2,7 +2,6 @@
 ## vim:set ts=4 sw=4 et:
 set -e; set -o pipefail
 
-# Support for Travis CI -- https://travis-ci.org/upx/upx/builds
 # Copyright (C) Markus Franz Xaver Johannes Oberhumer
 
 if [[ $TRAVIS_OS_NAME == osx ]]; then
diff --git a/.github/travis_init.sh b/.github/travis_init.sh
index 33e03bc0..d32e2a9f 100644
--- a/.github/travis_init.sh
+++ b/.github/travis_init.sh
@@ -1,6 +1,5 @@
 ## vim:set ts=4 sw=4 et:
 
-# Support for Travis CI -- https://travis-ci.org/upx/upx/builds
 # Copyright (C) Markus Franz Xaver Johannes Oberhumer
 
 #set -x # debug
@@ -130,6 +129,15 @@ if [[ -n $BM_CROSS ]]; then
                 [[ -z $upx_wine ]] && upx_wine="wine"
                 x=x86_64-w64-mingw32; AR="$x-ar"; CC="$x-gcc -m64"; CXX="$x-g++ -m64" ;;
         esac
+    elif egrep -q '^PRETTY_NAME="?Ubuntu 20\.04' /etc/os-release; then
+        case $BM_CROSS-$BM_C in
+            x86_64-w64-mingw32-gcc-9)
+                export upx_EXTRA_CPPFLAGS="-D__USE_MINGW_ANSI_STDIO=1"
+                export upx_EXTRA_LDFLAGS="-static"
+                upx_exeext=.exe
+                [[ -z $upx_wine ]] && upx_wine="wine64"
+                x=x86_64-w64-mingw32; AR="$x-ar"; CC="$x-gcc -m64"; CXX="$x-g++ -m64" ;;
+        esac
     fi
 fi # BM_CROSS
 if [[ "$CC" == "false" ]]; then # generic
diff --git a/.github/travis_testsuite_1.sh b/.github/travis_testsuite_1.sh
index de1e024e..fd331bc3 100644
--- a/.github/travis_testsuite_1.sh
+++ b/.github/travis_testsuite_1.sh
@@ -2,7 +2,6 @@
 ## vim:set ts=4 sw=4 et:
 set -e; set -o pipefail
 
-# Support for Travis CI -- https://travis-ci.org/upx/upx/builds
 # Copyright (C) Markus Franz Xaver Johannes Oberhumer
 
 #
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5bfa51e1..b7d07654 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,7 +14,7 @@ on:
   workflow_dispatch:
 
 jobs:
-  job-ci-rebuild-and-verify-stubs:
+  job-rebuild-and-verify-stubs:
     name: 'Rebuild stubs'
     runs-on: ubuntu-16.04
     steps:
@@ -34,8 +34,8 @@ jobs:
         run: |
           env C=gcc X=rebuild-stubs TRAVIS_OS_NAME=linux bash ./.github/travis_build.sh
 
-  job-ci-linux-toolchains:
-    needs: [ job-ci-rebuild-and-verify-stubs ]
+  job-linux-toolchains:
+    needs: [ job-rebuild-and-verify-stubs ]
     name: ${{ matrix.name }}
     runs-on: ${{ matrix.os }}
 
@@ -71,7 +71,7 @@ jobs:
         run: |
           cd ..; mkdir -p deps build/github; cd deps
           wget -q -O - https://github.com/upx/upx/releases/download/v3.00/ucl-1.03.tar.xz | tar -xJ
-          git clone --depth=1 https://github.com/upx/upx-testsuite
+          git clone --depth=1 --single-branch https://github.com/upx/upx-testsuite
 
       - name: 'Build'
         run: |
@@ -84,8 +84,52 @@ jobs:
           export C=${{matrix.C}} B=${{matrix.B}} T=${{matrix.T}} X=${{matrix.X}} TRAVIS_OS_NAME=linux
           bash ./.github/travis_testsuite_1.sh
 
-  job-ci-windows-toolchains:
-    needs: [ job-ci-rebuild-and-verify-stubs ]
+  job-windows-cross-toolchains:
+    needs: [ job-rebuild-and-verify-stubs ]
+    name: ${{ matrix.name }}
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - { name: amd64-win64-gcc-9, os: ubuntu-20.04, CROSS: x86_64-w64-mingw32, C: gcc-9, T: wine }
+
+    steps:
+      - name: 'Install extra packages'
+        run: |
+          uname -a; pwd; id; umask
+          export DEBIAN_FRONTEND=noninteractive
+          sudo dpkg --add-architecture i386
+          sudo apt-get update
+          sudo apt-get install -y binutils-mingw-w64-x86-64 g++-mingw-w64-x86-64 wine wine64
+
+      - name: 'Check out code'
+        uses: actions/checkout@v2
+        with: { submodules: true }
+
+      - name: 'Prepare sources'
+        run: |
+          cd ..; mkdir -p deps build/github; cd deps
+          wget -q -O - https://github.com/upx/upx/releases/download/v3.00/ucl-1.03.tar.xz | tar -xJ
+          wget -q -O - https://github.com/upx/upx/releases/download/v3.00/zlib-1.2.11.tar.xz | tar -xJ
+          git clone --depth=1 --single-branch https://github.com/upx/upx-testsuite
+
+      - name: 'Build'
+        run: |
+          export C=${{matrix.C}} B=${{matrix.B}} T=${{matrix.T}} X=${{matrix.X}} TRAVIS_OS_NAME=linux
+          export CROSS=${{matrix.CROSS}}
+          export BUILD_LOCAL_UCL=1
+          bash ./.github/travis_build.sh
+
+      - name: 'Run test suite'
+        run: |
+          export C=${{matrix.C}} B=${{matrix.B}} T=${{matrix.T}} X=${{matrix.X}} TRAVIS_OS_NAME=linux
+          export CROSS=${{matrix.CROSS}}
+          bash ./.github/travis_testsuite_1.sh
+
+  job-windows-toolchains:
+    needs: [ job-rebuild-and-verify-stubs ]
     name: ${{ matrix.name }}
     runs-on: ${{ matrix.os }}