diff --git a/src/jrd/evl.cpp b/src/jrd/evl.cpp
index b22a32c9c9..01e8719463 100644
--- a/src/jrd/evl.cpp
+++ b/src/jrd/evl.cpp
@@ -3933,7 +3933,7 @@ static void init_agg_distinct(thread_db* tdbb, const jrd_nod* node)
 	SORT_fini(asb_impure->iasb_sort_handle);
 
 	asb_impure->iasb_sort_handle =
-		SORT_init(tdbb->getDatabase(), &request->req_sorts, ROUNDUP_LONG(asb->asb_length),
+		SORT_init(tdbb->getDatabase(), &request->req_sorts, asb->asb_length,
 		(asb->asb_intl ? 2 : 1), 1, sort_key, reject_duplicate, 0);
 }
 
diff --git a/src/jrd/opt.cpp b/src/jrd/opt.cpp
index 5373b5df85..28057eac3f 100644
--- a/src/jrd/opt.cpp
+++ b/src/jrd/opt.cpp
@@ -4151,6 +4151,8 @@ static RecordSource* gen_aggregate(thread_db* tdbb, OptimizerBlk* opt, jrd_nod*
 			else
 				asb->asb_length += sort_key->skd_length;
 
+			asb->asb_length = ROUNDUP(asb->asb_length, sizeof(SLONG));
+
 			sort_key->skd_flags = SKD_ascending;
 			asb->nod_impure = CMP_impure(csb, sizeof(impure_agg_sort));
 			asb->asb_desc = *desc;