diff --git a/src/jrd/tra.cpp b/src/jrd/tra.cpp
index d455b0792b..9e7773e676 100644
--- a/src/jrd/tra.cpp
+++ b/src/jrd/tra.cpp
@@ -569,7 +569,7 @@ void TRA_get_inventory(thread_db* tdbb, UCHAR* bit_vector, TraNumber base, TraNu
 	{
 		ULONG l = base % trans_per_tip;
 		const UCHAR* q = tip->tip_transactions + TRANS_OFFSET(l);
-		l = TRANS_OFFSET(MIN((top + TRA_MASK - base), trans_per_tip - l));
+		l = TRANS_OFFSET(MIN((top + TRA_MASK + 1 - base), trans_per_tip - l));
 		memcpy(p, q, l);
 		p += l;
 	}
@@ -588,7 +588,7 @@ void TRA_get_inventory(thread_db* tdbb, UCHAR* bit_vector, TraNumber base, TraNu
 		TPC_update_cache(tdbb, tip, sequence - 1);
 		if (p)
 		{
-			const ULONG l = TRANS_OFFSET(MIN((top + TRA_MASK - base), trans_per_tip));
+			const ULONG l = TRANS_OFFSET(MIN((top + TRA_MASK + 1 - base), trans_per_tip));
 			memcpy(p, tip->tip_transactions, l);
 			p += l;
 		}