diff --git a/eclair/utils.sh b/eclair/utils.sh
index 61cea74..99481e6 100644
--- a/eclair/utils.sh
+++ b/eclair/utils.sh
@@ -81,3 +81,10 @@
 
     eclair_make_report_self_contained ${ECLAIR_OUTPUT_DIR}/../full_html
 }
+
+eclair_make_delta_report() {
+    dir1=$1
+    dir2=$2
+    diff -I '^Timestamp:' -x frames.txt -x files.txt -x explain.txt \
+        -ur ${WORKSPACE}/$dir1/summary_txt/ ${WORKSPACE}/$dir2/summary_txt/ > ${WORKSPACE}/$dir2/summary_txt.diff || true
+}