diff --git a/.dockerignore b/.dockerignore
index c5abb5ff..33f33614 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -2,3 +2,5 @@
 !ci/*
 !tools/aseprite/*
 !requirements.txt
+!gradle/*
+!gradlew
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index bbf5ef11..13ac0005 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -11,8 +11,8 @@ jobs:
         run: ci/build-docker-image
         shell: bash
       - name: Build
-        run: ci/docker-build-game SNAPSHOT=1
         shell: bash
+        run: ci/docker-build-game SNAPSHOT=1
       - name: Upload
         if: github.ref == 'refs/heads/master'
         run: make upload SNAPSHOT=1
diff --git a/Dockerfile b/Dockerfile
index 97513ac6..169d0c12 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,10 +10,19 @@ RUN apt-get update \
         openjdk-8-jdk \
         python3-pip \
         python3-setuptools \
+        unzip \
         zip
 
 COPY requirements.txt /src/
 RUN pip3 install -r /src/requirements.txt
 
+# Install gradle so that we don't have to do it for each build
+COPY gradle /src/gradle
+COPY gradlew /src
+RUN /src/gradlew
+
+COPY ci/install-android-sdk /src
+RUN /src/install-android-sdk
+
 WORKDIR /root
 ENTRYPOINT ["/bin/bash"]
diff --git a/ci/build-docker-image b/ci/build-docker-image
index ed1b6ba3..9a87892e 100755
--- a/ci/build-docker-image
+++ b/ci/build-docker-image
@@ -1,4 +1,4 @@
 #!/bin/sh
 set -e
 cd $(dirname $0)
-docker build -t pixelwheels ..
+docker build --tag pixelwheels ..
diff --git a/ci/docker-build-game b/ci/docker-build-game
index b40ee2eb..e1899753 100755
--- a/ci/docker-build-game
+++ b/ci/docker-build-game
@@ -5,8 +5,24 @@ cd $(dirname $0)
 
 make_args=$@
 
+SRC_DIR=$PWD/..
+SIGNING_GRADLE=$SRC_DIR/android/signing.gradle
+LOCAL_PROPERTIES=$SRC_DIR/local.properties
+
+# If SIGNING_GRADLE does not exist, gradle fails to run tests
+if [ ! -e "$SIGNING_GRADLE" ]; then
+    echo "Creating empty $SIGNING_GRADLE"
+    touch $SIGNING_GRADLE
+fi
+
+if [ ! -e "$LOCAL_PROPERTIES" ]; then
+    echo "Creating $LOCAL_PROPERTIES"
+    # Must match ci/install-android-sdk
+    echo "sdk.dir=/opt/android-sdk" > "$LOCAL_PROPERTIES"
+fi
+
 # Do not use "make dist" for now because current Docker does not support building apk yet
 docker run --rm \
-    -v $PWD/..:/src/pixelwheels \
+    -v $SRC_DIR:/src/pixelwheels \
     pixelwheels \
-    -c "make GRADLEW='./gradlew --console plain' -C /src/pixelwheels codingstyle-check assets packer desktop-dist $make_args"
+    -c "make GRADLEW='./gradlew --console plain' -C /src/pixelwheels check assets packer desktop-dist $make_args"
diff --git a/ci/install-android-sdk b/ci/install-android-sdk
new file mode 100755
index 00000000..592d4069
--- /dev/null
+++ b/ci/install-android-sdk
@@ -0,0 +1,33 @@
+#!/bin/bash
+set -euo pipefail
+
+TOOLS_URL=https://dl.google.com/android/repository/commandlinetools-linux-6858069_latest.zip
+
+# Must match android/build.gradle
+PACKAGES="
+build-tools;29.0.3
+platforms;android-29
+"
+
+ANDROID_SDK=/opt/android-sdk
+TOOLS_DIR=$ANDROID_SDK/cmdline-tools
+SDKMANAGER=$TOOLS_DIR/bin/sdkmanager
+
+TOOLS_ZIP=tools.zip
+
+mkdir -p $ANDROID_SDK
+cd $ANDROID_SDK
+
+if [ ! -d $TOOLS_DIR ] ; then
+    if [ ! -e $TOOLS_ZIP ] ; then
+        echo "Downloading command-line tools from $TOOLS_URL"
+        curl $TOOLS_URL --output $TOOLS_ZIP
+    fi
+    echo "Unpacking command-line tools"
+    unzip -q $TOOLS_ZIP
+fi
+
+for pkg in $PACKAGES ; do
+    echo "Installing $pkg"
+    echo Y | $SDKMANAGER --sdk_root=$ANDROID_SDK "$pkg"
+done