diff --git a/.appveyor.yml b/.appveyor.yml
index a82710c2..b10afe49 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -5,6 +5,7 @@ os: Visual Studio 2015
 
 branches:
   except:
+    - /^github.*/
     - /^gitlab.*/
     - /^travis.*/
 
diff --git a/.github/travis_init.sh b/.github/travis_init.sh
index 1b60d282..b6a5e34c 100644
--- a/.github/travis_init.sh
+++ b/.github/travis_init.sh
@@ -147,12 +147,16 @@ if [[ -z $BM_CROSS ]]; then
                 v=${BM_C:6:3}; CC="clang-$v"; CXX="clang++-$v"; SCAN_BUILD="scan-build-$v" ;;
             clang-[789]-m??)
                 v=${BM_C:6:1}; CC="clang-$v"; CXX="clang++-$v"; SCAN_BUILD="scan-build-$v" ;;
+            clang-1[0-9]-m??)
+                v=${BM_C:6:2}; CC="clang-$v"; CXX="clang++-$v"; SCAN_BUILD="scan-build-$v" ;;
             gcc | gcc-m?? | gcc-mx32)
                 CC="gcc"; CXX="g++" ;; # standard system compiler
             gcc-[34].[0-9]-m?? | gcc-[34].[0-9]-mx32)
                 v=${BM_C:4:3}; CC="gcc-$v"; CXX="g++-$v" ;;
             gcc-[56789]-m?? | gcc-[56789]-mx32)
                 v=${BM_C:4:1}; CC="gcc-$v"; CXX="g++-$v" ;;
+            gcc-1[0-9]-m?? | gcc-1[0-9]-mx32)
+                v=${BM_C:4:2}; CC="gcc-$v"; CXX="g++-$v" ;;
         esac
     fi
 fi
@@ -188,7 +192,7 @@ mkbuilddirs() {
 # search for an existing $toptop_builddir
 if [[ -z $toptop_builddir ]]; then
     for d in . ..;  do
-        for subdir in "local" appveyor circle gitlab travis .; do
+        for subdir in "local" appveyor circle github gitlab travis .; do
             dd=$d/build/$subdir
             if [[ -d $dd ]]; then
                 toptop_builddir=$(readlink -en -- "$dd")
diff --git a/.github/workflows/ci-build-linux.yml b/.github/workflows/ci-build-linux.yml
new file mode 100644
index 00000000..257b14ce
--- /dev/null
+++ b/.github/workflows/ci-build-linux.yml
@@ -0,0 +1,63 @@
+# Support for GitHub Actions -- https://github.com/features/actions
+# Copyright (C) Markus Franz Xaver Johannes Oberhumer
+
+name: GitHub CI
+
+on:
+  push:
+    branches:
+      - '*'
+      - '!appveyor*'
+      - '!gitlab*'
+      - '!travis*'
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+# A workflow run is made up of one or more jobs that can run sequentially or in parallel
+jobs:
+  # This workflow contains a single job called "build"
+  build:
+
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - { os: ubuntu-20.04, C: clang-10-m64 }
+          - { os: ubuntu-20.04, C: gcc-10-m64 }
+          #- { os: ubuntu-20.04, X: rebuild-stubs }
+
+    # Steps represent a sequence of tasks that will be executed as part of the job
+    steps:
+      #if: contains(matrix.os, 'ubuntu')
+
+      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
+      - uses: actions/checkout@v2
+        with: { submodules: true }
+
+      - name: 'Step: prepare sources'
+        run: |
+          export C=${{matrix.C}} B=${{matrix.B}} T=${{matrix.T}} X=${{matrix.X}} TRAVIS_OS_NAME=linux
+          uname -a; pwd; id; umask
+          #cat /etc/os-release || true
+          #env
+          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-1.2.8.tar.xz | tar -xJ
+          git clone https://github.com/upx/upx-testsuite
+          if [[ $X =~ (^|\+)rebuild-stubs($|\+) ]]; then
+            wget -q -O - https://github.com/upx/upx-stubtools/releases/download/v20160918/bin-upx-20160918.tar.xz | tar -xJ
+          fi
+
+      - name: 'Step: build'
+        run: |
+          export C=${{matrix.C}} B=${{matrix.B}} T=${{matrix.T}} X=${{matrix.X}} TRAVIS_OS_NAME=linux
+          bash ./.github/travis_build.sh
+
+      - name: 'Step: run testsuite'
+        run: |
+          export C=${{matrix.C}} B=${{matrix.B}} T=${{matrix.T}} X=${{matrix.X}} TRAVIS_OS_NAME=linux
+          bash ./.github/travis_testsuite_1.sh
+
+# vim:set ts=2 sw=2 et:
diff --git a/.travis.yml b/.travis.yml
index 08bc96b8..3473d48c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,6 +11,7 @@ notifications: { email: { on_success: never, on_failure: change } }
 branches:
   except:
     - /^appveyor.*/
+    - /^github.*/
     - /^gitlab.*/
 
 # Ubuntu 12.04 LTS "Precise"