diff --git a/src/plugins/fts-squat/squat-uidlist.c b/src/plugins/fts-squat/squat-uidlist.c
index 923835ee8d..6682c2035e 100644
--- a/src/plugins/fts-squat/squat-uidlist.c
+++ b/src/plugins/fts-squat/squat-uidlist.c
@@ -195,8 +195,11 @@ uidlist_write_array(struct ostream *output, const uint32_t *uid_list,
 		prev = 0;
 		for (i = 0; i < uid_count; i++) {
 			uid = uid_list[i];
-			if (unlikely((uid & ~UID_LIST_MASK_RANGE) < prev))
+			if (unlikely((uid & ~UID_LIST_MASK_RANGE) < prev)) {
+				if (!datastack)
+					i_free(uidbuf);
 				return -1;
+			}
 			if ((uid & UID_LIST_MASK_RANGE) == 0) {
 				squat_pack_num(&bufp, (uid - prev) << 1);
 				prev = uid + 1;