diff --git a/plakar-incus-backup.sh b/plakar-incus-backup.sh
index af0c29b..9379053 100755
--- a/plakar-incus-backup.sh
+++ b/plakar-incus-backup.sh
@@ -52,6 +52,18 @@ export PLAKAR_PASSPHRASE
 
 rc=0
 
+# The plakar pkg backend has been observed to silently expel an
+# installed plugin (its reload path deletes the ptar when the cache
+# re-extraction fails — seen 2026-08-24). Self-heal from the kept
+# ptar instead of failing the nightly run with
+# "unsupported importer protocol".
+if ! plakar pkg list 2>/dev/null | grep -q "^incus@"; then
+    PTAR=$(ls -t /root/incus-plugin/incus_v*.ptar 2>/dev/null | head -1)
+    echo "incus plugin missing — reinstalling ${PTAR:-<no ptar found>}" >&2
+    [ -n "$PTAR" ] && plakar pkg add "$PTAR" \
+        || { echo "incus plugin reinstall failed" >&2; exit 1; }
+fi
+
 log "backup @$SOURCE -> $KLOSET"
 plakar -quiet at "$KLOSET" backup -tag "$SOURCE" "@$SOURCE" \
     || { echo "backup @$SOURCE failed" >&2; rc=1; }