diff --git a/linux/build/scripts/build-inner.sh b/linux/build/scripts/build-inner.sh
index 27c9880..bff27fa 100755
--- a/linux/build/scripts/build-inner.sh
+++ b/linux/build/scripts/build-inner.sh
@@ -228,13 +228,18 @@ post_process_for_reproducibility() {
     # step (run #4278's TOC diff caught both: 21:27 vs 21:44).
     # `-volume_date` covers the volume-descriptor-level dates that
     # xorriso also stamps on -commit.
+    # `-alter_date_r` takes a variable-length path list and needs `--`
+    # to terminate it — without that, the next `-volume_date` is
+    # interpreted as a path, producing
+    #     FAILURE : Cannot find path '/-volume_date' in loaded ISO image
+    # (caught on run #4279).
     sudo --non-interactive xorriso \
         -return_with SORRY 0 \
         -indev   "${iso_file}" \
         -outdev  "${new_iso}" \
         -boot_image any keep \
         -update  "${new_sqfs}" /live/filesystem.squashfs \
-        -alter_date_r m "=${SOURCE_DATE_EPOCH}" / \
+        -alter_date_r m "=${SOURCE_DATE_EPOCH}" / -- \
         -volume_date c "=${SOURCE_DATE_EPOCH}" \
         -volume_date m "=${SOURCE_DATE_EPOCH}" \
         -commit