diff --git a/build_image b/build_image
index 86f9b0a08c..891aca3d28 100755
--- a/build_image
+++ b/build_image
@@ -103,7 +103,8 @@ fi
 
 # Check that the build root is sane.
 if [[ ${skip_test_build_root} -ne 1 ]]; then
-  "${BUILD_LIBRARY_DIR}/test_build_root" --root="${BOARD_ROOT}"
+  info "Checking build root"
+  test_image_content "${BOARD_ROOT}"
 fi
 
 # Hack to fix bug where x86_64 CHOST line gets incorrectly added.
diff --git a/build_library/test_build_root b/build_library/test_build_root
index cac339ea55..57aa6d72cd 100755
--- a/build_library/test_build_root
+++ b/build_library/test_build_root
@@ -6,12 +6,13 @@
 
 SCRIPT_ROOT=$(readlink -f $(dirname "$0")/..)
 . "${SCRIPT_ROOT}/common.sh" || exit 1
+. "${BUILD_LIBRARY_DIR}/test_image_content.sh" || exit 1
 
 # We're invoked only by build_image, which runs in the chroot
 assert_inside_chroot
 
 # Flags
-DEFINE_string root ""      \
+DEFINE_string root "${DEFAULT_BOARD+/build/${DEFAULT_BOARD}}" \
   "The root file system to check."
 
 # Parse command line
@@ -21,26 +22,8 @@ eval set -- "${FLAGS_ARGV}"
 # Die on any errors
 switch_to_strict_mode
 
-# Check all parts of a pipe
-set -o pipefail
-
-ROOT="$FLAGS_root"
-if [[ ! -d "$ROOT" ]]; then
-  die_notrace "Root FS does not exist ($ROOT)"
+if [[ ! -d "$FLAGS_root" ]]; then
+  die_notrace "Root FS does not exist ($FLAGS_root)"
 fi
 
-ROOT_BINARIES=(
-  /boot/vmlinuz
-  /bin/sed
-)
-
-EXITCODE=0
-for i in "${BINARIES[@]}"; do
-  i="${ROOT}${i}"
-  if ! [[ -f $i ]]; then
-    error "cannot find $i"
-    EXITCODE=1
-  fi
-done
-
-exit $EXITCODE
+test_image_content "$FLAGS_root"
diff --git a/build_packages b/build_packages
index 785b5306fd..81d3926cd1 100755
--- a/build_packages
+++ b/build_packages
@@ -128,6 +128,7 @@ fi
 # set BOARD and BOARD_ROOT
 . "${BUILD_LIBRARY_DIR}/toolchain_util.sh" || exit 1
 . "${BUILD_LIBRARY_DIR}/board_options.sh" || exit 1
+. "${BUILD_LIBRARY_DIR}/test_image_content.sh" || exit 1
 
 # Setup all the emerge command/flags.
 EMERGE_FLAGS=( -uDNv --backtrack=30 --select )
@@ -209,9 +210,11 @@ fi
 info "Merging board packages now"
 sudo -E "${EMERGE_CMD[@]}" "${EMERGE_FLAGS[@]}" "${PACKAGES[@]}"
 
+info "Checking build root"
+test_image_content "${BOARD_ROOT}"
+
 # upload packages if enabled
 upload_packages
 
-echo "Builds complete"
+info "Builds complete"
 command_completed
-echo "Done"