diff --git a/external/db_drivers/liblmdb/mdb_load.c b/external/db_drivers/liblmdb/mdb_load.c
index e900ae660..a2fee1cee 100644
--- a/external/db_drivers/liblmdb/mdb_load.c
+++ b/external/db_drivers/liblmdb/mdb_load.c
@@ -445,7 +445,7 @@ int main(int argc, char *argv[])
 			if (rc == MDB_KEYEXIST && putflags)
 				continue;
 			if (rc) {
-				fprintf(stderr, "mdb_cursor_put failed, error %d %s\n", rc, mdb_strerror(rc));
+				fprintf(stderr, "%s: line %"Yu": mdb_cursor_put failed, error %d %s\n", prog, lineno, rc, mdb_strerror(rc));
 				goto txn_abort;
 			}
 			batch++;
@@ -466,9 +466,11 @@ int main(int argc, char *argv[])
 					fprintf(stderr, "mdb_cursor_open failed, error %d %s\n", rc, mdb_strerror(rc));
 					goto txn_abort;
 				}
-				if (appflag & MDB_APPENDDUP) {
+				if (append) {
 					MDB_val k, d;
 					mdb_cursor_get(mc, &k, &d, MDB_LAST);
+					memcpy(prevk.mv_data, k.mv_data, k.mv_size);
+					prevk.mv_size = k.mv_size;
 				}
 				batch = 0;
 			}