diff --git a/integration-tests/metrics-v4.2.19.sh b/integration-tests/metrics-v4.2.19.sh
index afed0bbe425..64f75f6f6b2 100755
--- a/integration-tests/metrics-v4.2.19.sh
+++ b/integration-tests/metrics-v4.2.19.sh
@@ -14,6 +14,8 @@ fi
 do_sync="$([ "${#}" = 0 ] || [ "${1:-}" != '--sync' ] || echo 1)"
 report_directory="$([ "${#}" = 0 ] || ([ -z "${do_sync}" ] && echo "${1}") || ([ "${#}" = 1 ] || echo "${2}"))"
 
+# XXX: We exclude the CollectorMutability and the Immutable*|Preconditions*|StringRules.StringIsNullOrEmpty refaster rules
+# as they introduce changes that expect guava to be on the classpath.
 patch_flags="-Xep:CollectorMutability:OFF -XepOpt:Refaster:NamePattern=^((?!(Immutable|Preconditions|StringRules\.StringIsNullOrEmpty)).*)"
 
 "$(dirname ${0})"/integration-test.sh "$test_name" "$project" "$repository" "$revision" "" "${patch_flags}" "" "" "$do_sync" "$report_directory"