diff --git a/tools/image-tag b/tools/image-tag
index 6e2deb4f2c177..406b0740e0d73 100755
--- a/tools/image-tag
+++ b/tools/image-tag
@@ -6,6 +6,8 @@ set -o pipefail
 
 WIP=$(git diff --quiet || echo '-WIP')
 BRANCH=$(git rev-parse --abbrev-ref HEAD | sed 's#/#-#g')
+# When 7 chars are not enough to be unique, git automatically uses more.
+# We are forcing to 7 here, as we are doing for grafana/grafana as well.
 SHA=$(git rev-parse --short=7 HEAD | head -c7)
 
 # If this is a tag, use it,                      otherwise branch-hash