diff --git a/lib/cros_workon_common.sh b/lib/cros_workon_common.sh
index 45f3c13703..129bc0c1d8 100644
--- a/lib/cros_workon_common.sh
+++ b/lib/cros_workon_common.sh
@@ -6,16 +6,29 @@
 
 # Common library for functions used by workon tools.
 
-show_workon_ebuilds() {
+find_workon_ebuilds() {
   pushd "${BOARD_DIR}"/etc/ 1> /dev/null
   source make.conf
   popd 1> /dev/null
   local CROS_OVERLAYS="${PORTDIR_OVERLAY}"
 
+  # NOTE: overlay may be a symlink, and we have to use ${overlay}/
   for overlay in ${CROS_OVERLAYS}; do
-    pushd ${overlay} 1> /dev/null
-    find . -name '*.ebuild' | xargs fgrep cros-workon | \
-      awk -F / '{ print $2 "/" $3 }' | uniq | sort
-    popd 1> /dev/null
+    # only look up ebuilds named 9999 to eliminate duplicates
+    find ${overlay}/ -name '*9999.ebuild' | xargs fgrep cros-workon | \
+      sed -e 's/\([.]ebuild\):.*/\1/'|uniq
   done
 }
+
+# wrapper script that caches the result of find_workon_ebuilds()
+show_workon_ebuilds_files() {
+  if [ -z "${CROS_ALL_EBUILDS}" ]; then
+    CROS_ALL_EBUILDS=$(find_workon_ebuilds)
+  fi
+  echo "${CROS_ALL_EBUILDS}"
+}
+
+show_workon_ebuilds() {
+  show_workon_ebuilds_sources | \
+    sed -e 's/.*\/\([^/]*\)\/\([^/]*\)\/.*\.ebuild/\1\/\2/'| sort
+}