diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e9d151a..3cde1a7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,9 +11,22 @@ jobs:
       - uses: actions/setup-go@v2
         with:
           go-version: 1.16.5
+      - run: |
+          sudo apt-get install -y gcc-aarch64-linux-gnu gcc-arm-linux-gnueabihf
+          sudo dpkg --add-architecture arm64
+          sudo dpkg --add-architecture armhf
+          echo '
+          deb [arch=arm64,armhf] http://ports.ubuntu.com/ubuntu-ports/ focal main restricted universe multiverse
+          deb [arch=arm64,armhf] http://ports.ubuntu.com/ubuntu-ports/ focal-updates main restricted universe multiverse
+          ' | sudo tee /etc/apt/sources.list.d/arm.list
+          sudo apt-get update || true
+          sudo apt-get install libgmp-dev:arm64 libgmp-dev:armhf
       - uses: actions/checkout@v2
       - name: go build
-        run: go build -v -ldflags '-w -s -extldflags -static' -o redpwnpow-linux-amd64 ./cmd/redpwnpow
+        run: |
+          go build -v -ldflags '-w -s -extldflags -static' -o redpwnpow-linux-amd64 ./cmd/redpwnpow
+          CC=aarch64-linux-gnu-gcc CGO_ENABLED=1 GOARCH=arm64 go build -v -ldflags '-w -s -extldflags -static' -o redpwnpow-linux-arm64 ./cmd/redpwnpow
+          CC=arm-linux-gnueabihf-gcc CGO_ENABLED=1 GOARCH=arm go build -v -ldflags '-w -s -extldflags -static' -o redpwnpow-linux-armv6l ./cmd/redpwnpow
       - uses: actions/upload-artifact@v2
         with:
           name: linux
diff --git a/cmd/redpwnpow/run.sh b/cmd/redpwnpow/run.sh
index 1087508..78a834b 100755
--- a/cmd/redpwnpow/run.sh
+++ b/cmd/redpwnpow/run.sh
@@ -4,10 +4,15 @@
 
 set -e
 version=VERSION
-challenge=$1
 run() {
   case $(uname | tr '[:upper:]' '[:lower:]') in
-    linux*) release=linux-amd64;;
+    linux*)
+      case $(uname -m) in
+        x86_64) release=linux-amd64;;
+        aarch64) release=linux-arm64;;
+        arm*) release=linux-armv6l;;
+        *) echo unknown linux architecture >&2; exit 1
+      esac;;
     darwin*) release=darwin-amd64;;
     msys*|mingw*|cygwin*) release=windows-amd64.exe;;
     *) echo unknown operating system >&2; exit 1
@@ -16,6 +21,6 @@ run() {
   mkdir -p "$cache_root"
   cache_path=$cache_root/redpwnpow-$version-$release
   [ -e "$cache_path" ] || curl -sSfLo "$cache_path" "https://github.com/redpwn/pow/releases/download/$version/redpwnpow-$release" && chmod u+x "$cache_path"
-  "$cache_path" "$challenge"
+  "$cache_path" "$@"
 }
-run
+run "$@"