diff --git a/build_kzip.bash b/build_kzip.bash
index 5364e7f5d..22ff50453 100755
--- a/build_kzip.bash
+++ b/build_kzip.bash
@@ -3,13 +3,13 @@
 # Build kzip files (source files for the indexing pipeline) for the given configuration,
 # merge them and place the resulting all.kzip into $DIST_DIR.
 # It is assumed that the current directory is the top of the source tree.
-# The following enviromnet variables affect the result:
-#   TARGET_PRODUCT        target device name, e.g., `aosp_blueline`
+# The following environment variables affect the result:
+#   TARGET_PRODUCT        target device name, e.g., 'aosp_blueline'
 #   TARGET_BUILD_VARIANT  variant, e.g., `userdebug`
 #   OUT_DIR               where the build is happening (./out if not specified)
 #   DIST_DIR              where the resulting all.kzip will be placed
-#   XREF_CORPUS           source code repository URI, e.g.,
-#                        `android.googlesource.com/platform/superproject`
+#   XREF_CORPUS           source code repository URI, e.g., 'android.googlesource.com/platform/superproject'
+#   BUILD_NUMBER          build number, used to generate unique ID (will use UUID if not set)
 
 # The extraction might fail for some source files, so run with -k
 build/soong/soong_ui.bash --build-mode --all-modules --dir=$PWD -k merge_zips xref_cxx xref_java
@@ -23,3 +23,4 @@ declare -r kzip_count=$(find $OUT_DIR -name '*.kzip' | wc -l)
 # TODO(asmundak): this should be done by soong.
 declare -r allkzip=all.kzip
 "${OUT_DIR:-out}/soong/host/linux-x86/bin/merge_zips" "$DIST_DIR/$allkzip" @<(find $OUT_DIR -name '*.kzip')
+echo "${BUILD_NUMBER:-$(uuidgen)}" >"$DIST_DIR/revision.txt"