diff --git a/build/apex/runtests.sh b/build/apex/runtests.sh
new file mode 100755
index 0000000..6af2a8b
--- /dev/null
+++ b/build/apex/runtests.sh
@@ -0,0 +1,201 @@
+#!/bin/bash
+
+# Copyright (C) 2018 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Run Android Runtime APEX tests.
+
+function say {
+  echo "$0: $*"
+}
+
+function die {
+  echo "$0: $*"
+  exit 1
+}
+
+which guestmount >/dev/null && which guestunmount >/dev/null && which virt-filesystems >/dev/null \
+  || die "This script requires 'guestmount', 'guestunmount',
+and 'virt-filesystems' from libguestfs. On Debian-based systems, these tools
+can be installed with:
+
+   sudo apt-get install libguestfs-tools
+"
+[[ -n "$ANDROID_PRODUCT_OUT" ]] \
+  || die "You need to source and lunch before you can use this script."
+
+# Fail early.
+set -e
+
+build_apex_p=true
+list_image_files_p=false
+
+function usage {
+  cat <<EOF
+Usage: $0 [OPTION]
+Build (optional) and run tests on Android Runtime APEX package (on host).
+
+  -s, --skip-build    skip the build step
+  -l, --list-files    list the contents of the ext4 image
+  -h, --help          display this help and exit
+
+EOF
+  exit
+}
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    (-s|--skip-build) build_apex_p=false;;
+    (-l|--list-files) list_image_files_p=true;;
+    (-h|--help) usage;;
+    (*) die "Unknown option: '$1'
+Try '$0 --help' for more information.";;
+  esac
+  shift
+done
+
+work_dir=$(mktemp -d)
+mount_point="$work_dir/image"
+
+# Garbage collection.
+function finish {
+  # Don't fail early during cleanup.
+  set +e
+  guestunmount "$mount_point"
+  rm -rf "$work_dir"
+}
+
+trap finish EXIT
+
+apex_module="com.android.runtime"
+
+# Build the Android Runtime APEX package (optional).
+$build_apex_p && say "Building package" && make "$apex_module"
+
+system_apexdir="$ANDROID_PRODUCT_OUT/system/apex"
+apex_package="$system_apexdir/$apex_module.apex"
+
+say "Extracting and mounting image"
+
+# Extract the image from the Android Runtime APEX.
+image_filename="image.img"
+unzip -q "$apex_package" "$image_filename" -d "$work_dir"
+mkdir "$mount_point"
+image_file="$work_dir/$image_filename"
+
+# Check filesystems in the image.
+image_filesystems="$work_dir/image_filesystems"
+virt-filesystems -a "$image_file" >"$image_filesystems"
+# We expect a single partition (/dev/sda) in the image.
+partition="/dev/sda"
+echo "$partition" | cmp "$image_filesystems" -
+
+# Mount the image from the Android Runtime APEX.
+guestmount -a "$image_file" -m "$partition" "$mount_point"
+
+# List the contents of the mounted image (optional).
+$list_image_files_p && say "Listing image files" && ls -ld "$mount_point" && tree -ap "$mount_point"
+
+say "Running tests"
+
+# Check that the mounted image contains a manifest.
+[[ -f "$mount_point/manifest.json" ]]
+
+function check_binary {
+  [[ -x "$mount_point/bin/$1" ]] || die "Cannot find binary '$1' in mounted image"
+}
+
+function check_multilib_binary {
+  # TODO: Use $TARGET_ARCH (e.g. check whether it is "arm" or "arm64") to improve
+  # the precision of this test?
+  [[ -x "$mount_point/bin/${1}32" ]] || [[ -x "$mount_point/bin/${1}64" ]] \
+    || die "Cannot find binary '$1' in mounted image"
+}
+
+function check_binary_symlink {
+  [[ -h "$mount_point/bin/$1" ]] || die "Cannot find symbolic link '$1' in mounted image"
+}
+
+function check_library {
+  # TODO: Use $TARGET_ARCH (e.g. check whether it is "arm" or "arm64") to improve
+  # the precision of this test?
+  [[ -f "$mount_point/lib/$1" ]] || [[ -f "$mount_point/lib64/$1" ]] \
+    || die "Cannot find library '$1' in mounted image"
+}
+
+# Check that the mounted image contains ART base binaries.
+check_multilib_binary dalvikvm
+# TODO: Does not work yet.
+: check_binary_symlink dalvikvm
+check_binary dex2oat
+check_binary dexoptanalyzer
+check_binary profman
+
+# Check that the mounted image contains ART tools binaries.
+check_binary dexdiag
+check_binary dexdump
+check_binary dexlist
+check_binary oatdump
+
+# Check that the mounted image contains ART debug binaries.
+check_binary dex2oatd
+check_binary dexoptanalyzerd
+check_binary profmand
+
+# Check that the mounted image contains ART libraries.
+check_library libart-compiler.so
+check_library libart.so
+check_library libopenjdkjvm.so
+check_library libopenjdkjvmti.so
+check_library libadbconnection.so
+# TODO: Should we check for these libraries too, even if they are not explicitly
+# listed as dependencies in the Android Runtime APEX module rule?
+check_library libartbase.so
+check_library libart-dexlayout.so
+check_library libart-disassembler.so
+check_library libdexfile.so
+check_library libprofile.so
+
+# Check that the mounted image contains ART debug libraries.
+check_library libartd-compiler.so
+check_library libartd.so
+check_library libdexfiled.so
+check_library libopenjdkd.so
+check_library libopenjdkjvmd.so
+check_library libopenjdkjvmtid.so
+check_library libadbconnectiond.so
+# TODO: Should we check for these libraries too, even if they are not explicitly
+# listed as dependencies in the Android Runtime APEX module rule?
+check_library libartbased.so
+check_library libartd-dexlayout.so
+check_library libprofiled.so
+
+# TODO: Should we check for other libraries, such as:
+#
+#   libbacktrace.so
+#   libbase.so
+#   liblog.so
+#   libsigchain.so
+#   libtombstoned_client.so
+#   libunwindstack.so
+#   libvixl-arm64.so
+#   libvixl-arm.so
+#   libvixld-arm64.so
+#   libvixld-arm.so
+#   ...
+#
+# ?
+
+say "Tests passed"