diff --git a/testing/geckodriver/.travis.yml b/testing/geckodriver/.travis.yml
index 743789841e3d..7d0c623b60ed 100644
--- a/testing/geckodriver/.travis.yml
+++ b/testing/geckodriver/.travis.yml
@@ -1,4 +1,9 @@
 language: generic
+cache:
+  directories:
+    - $HOME/.cargo
+    - $TRAVIS_BUILD_DIR/target
+    - $HOME/docker/
 
 matrix:
   include:
@@ -38,18 +43,21 @@ matrix:
           - gcc-mingw-w64-x86-64
           - binutils-mingw-w64-x86-64
           - libbz2-dev
+    - os: linux
+      env:
+        - TARGET=i686-pc-windows-gnu
+        - NAME=win32
+        - EXT=zip
+        - USE_DOCKER=1
+      dist: trusty
+      services:
+        - docker
     - os: osx
       env:
         - TARGET=x86_64-apple-darwin
         - NAME=macos
         - EXT=tar.gz
 
-install:
-  - export PATH="$PATH:$HOME/.cargo/bin"
-  - curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain=beta
-  - rustc -V
-  - cargo -V
-
 script:
   - bash ci.sh
 
diff --git a/testing/geckodriver/build.sh b/testing/geckodriver/build.sh
new file mode 100644
index 000000000000..186363e2beb8
--- /dev/null
+++ b/testing/geckodriver/build.sh
@@ -0,0 +1,148 @@
+set -ex
+
+print_versions() {
+    rustc -V
+    cargo -V
+}
+
+rustup_install() {
+    export PATH="$PATH:$HOME/.cargo/bin"
+    curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain=beta
+}
+
+# Add provided target to current Rust toolchain if it is not already
+# the default or installed.
+rustup_target_add() {
+    if ! rustup target list | grep -E "$1 \((default|installed)\)"
+    then
+        rustup target add $1
+    fi
+}
+
+setup_docker() {
+    apt-get -qq -y install zip
+    cd /mnt/host
+}
+
+# Configure rustc target for cross compilation.  Provided with a build
+# target, this will determine which linker to use for cross compilation.
+cargo_config() {
+    local prefix
+
+    case "$TARGET" in
+    aarch64-unknown-linux-gnu)
+        prefix=aarch64-linux-gnu
+        ;;
+    arm*-unknown-linux-gnueabihf)
+        prefix=arm-linux-gnueabihf
+        ;;
+    arm-unknown-linux-gnueabi)
+        prefix=arm-linux-gnueabi
+        ;;
+    mipsel-unknown-linux-musl)
+        prefix=mipsel-openwrt-linux
+        ;;
+    x86_64-pc-windows-gnu)
+        prefix=x86_64-w64-mingw32
+        ;;
+    *)
+        return
+        ;;
+    esac
+
+    mkdir -p ~/.cargo
+    cat >~/.cargo/config <<EOF
+[target.$TARGET]
+linker = "$prefix-gcc"
+EOF
+}
+
+# Build current crate for given target and print file type information.
+# If the second argument is set, a release build will be made.
+cargo_build() {
+    local mode
+    if [ -z "$2" ]
+    then
+        mode=debug
+    else
+        mode=release
+    fi
+
+    local modeflag
+    if [ "$mode" == "release" ]
+    then
+        modeflag=--release
+    fi
+
+    cargo build --target $1 $modeflag
+
+    file $(get_binary $1 $mode)
+}
+
+# Run current crate's tests if the current system supports it.
+cargo_test() {
+    if echo "$1" | grep -E "(i686|x86_64)-unknown-linux-(gnu|musl)|darwin"
+    then
+        cargo test --target $1
+    fi
+}
+
+# Returns relative path to binary
+# based on build target and type ("release"/"debug").
+get_binary() {
+    local ext
+    if [[ "$1" =~ "windows" ]]
+    then
+        ext=".exe"
+    fi
+    echo "target/$1/$2/geckodriver$ext"
+}
+
+# Create a compressed archive of the binary
+# for the given given git tag, build target, and build type.
+package_binary() {
+    local bin
+    bin=$(get_binary $2 $4)
+    cp $bin .
+
+    if [[ "$2" =~ "windows" ]]
+    then
+        filename="geckodriver-$1-$3.zip"
+        zip "$filename" geckodriver.exe
+        file "$filename"
+    else
+        filename="geckodriver-$1-$3.tar.gz"
+        tar zcvf "$filename" geckodriver
+        file "$filename"
+    fi
+    if [ ! -z "$USE_DOCKER" ]
+    then
+        chown "$USER_ID:$GROUP_ID" "$filename"
+    fi
+}
+
+main() {
+    if [ ! -z "$USE_DOCKER" ]
+    then
+        setup_docker
+        print_versions
+    else
+        rustup_install
+        print_versions
+        rustup_target_add $TARGET
+    fi
+
+    cargo_config $TARGET
+    cargo_build $TARGET
+    cargo_test $TARGET
+
+    # when something is tagged,
+    # also create a release build and package it
+    if [ ! -z "$TRAVIS_TAG" ]
+    then
+        cargo_build $TARGET 1
+        package_binary $TRAVIS_TAG $TARGET $NAME "release"
+    fi
+}
+
+main
diff --git a/testing/geckodriver/ci.sh b/testing/geckodriver/ci.sh
index 5ea11f03ecc4..2adb849651b5 100644
--- a/testing/geckodriver/ci.sh
+++ b/testing/geckodriver/ci.sh
@@ -1,119 +1,21 @@
 set -ex
 
-# Add provided target to current Rust toolchain if it is not already
-# the default or installed.
-rustup_target_add() {
-    if ! rustup target list | grep -E "$1 \((default|installed)\)"
-    then
-        rustup target add $1
-    fi
-}
-
-# Configure rustc target for cross compilation.  Provided with a build
-# target, this will determine which linker to use for cross compilation.
-cargo_config() {
-    local prefix
-
-    case "$TARGET" in
-    aarch64-unknown-linux-gnu)
-        prefix=aarch64-linux-gnu
-        ;;
-    arm*-unknown-linux-gnueabihf)
-        prefix=arm-linux-gnueabihf
-        ;;
-    arm-unknown-linux-gnueabi)
-        prefix=arm-linux-gnueabi
-        ;;
-    mipsel-unknown-linux-musl)
-        prefix=mipsel-openwrt-linux
-        ;;
-    x86_64-pc-windows-gnu)
-        prefix=x86_64-w64-mingw32
-        ;;
-    *)
-        return
-        ;;
-    esac
-
-    mkdir -p ~/.cargo
-    cat >>~/.cargo/config <<EOF
-[target.$TARGET]
-linker = "$prefix-gcc"
-EOF
-}
-
-# Build current crate for given target and print file type information.
-# If the second argument is set, a release build will be made.
-cargo_build() {
-    local mode
-    if [ -z "$2" ]
-    then
-        mode=debug
-    else
-        mode=release
-    fi
-
-    local modeflag
-    if [ "$mode" == "release" ]
-    then
-        modeflag=--release
-    fi
-
-    cargo build --target $1 $modeflag
-
-    file $(get_binary $1 $mode)
-}
-
-# Run current crate's tests if the current system supports it.
-cargo_test() {
-    if echo "$1" | grep -E "(i686|x86_64)-unknown-linux-(gnu|musl)|darwin"
-    then
-        cargo test --target $1
-    fi
-}
-
-# Returns relative path to binary
-# based on build target and type ("release"/"debug").
-get_binary() {
-    local ext
-    if [[ "$1" =~ "windows" ]]
-    then
-        ext=".exe"
-    fi
-    echo "target/$1/$2/geckodriver$ext"
-}
-
-# Create a compressed archive of the binary
-# for the given given git tag, build target, and build type.
-package_binary() {
-    local bin
-    bin=$(get_binary $2 $4)
-    cp $bin .
-
-    if [[ "$2" =~ "windows" ]]
-    then
-        zip geckodriver-$1-$3.zip geckodriver.exe
-        file geckodriver-$1-$3.zip
-    else
-        tar zcvf geckodriver-$1-$3.tar.gz geckodriver
-        file geckodriver-$1-$3.tar.gz
-    fi
-}
-
-main() {
-    rustup_target_add $TARGET
-
-    cargo_config $TARGET
-    cargo_build $TARGET
-    cargo_test $TARGET
-
-    # when something is tagged,
-    # also create a release build and package it
-    if [ ! -z "$TRAVIS_TAG" ]
-    then
-        cargo_build $TARGET 1
-        package_binary $TRAVIS_TAG $TARGET $NAME "release"
-    fi
-}
-
-main
+if [ ! -z "$USE_DOCKER" ]
+then
+    ls .
+    tag="port-of-rust/$TARGET/latest"
+    docker build https://github.com/alexcrichton/port-of-rust.git -f "$TARGET/Dockerfile" -t $tag
+    docker run\
+           -e USER="$USER"\
+           -e TARGET="$TARGET"\
+           -e USE_DOCKER=1\
+           -e NAME="$NAME"\
+           -e TRAVIS_TAG="$TRAVIS_TAG"\
+           -e USER_ID=$(id -u)\
+           -e GROUP_ID=$(id -g)\
+           -v $PWD:/mnt/host\
+           -i $tag\
+           bash -s -- < build.sh
+else
+    bash build.sh
+fi