diff --git a/src/jrd/btr.cpp b/src/jrd/btr.cpp
index b38e690e52..17f3c8f458 100644
--- a/src/jrd/btr.cpp
+++ b/src/jrd/btr.cpp
@@ -1542,6 +1542,8 @@ void BTR_reserve_slot(thread_db* tdbb, jrd_rel* relation, jrd_tra* transaction,
 	const Database* dbb = tdbb->tdbb_database;
 	CHECK_DBB(dbb);
 
+	fb_assert(relation && relation->rel_index_root);
+
 	// Get root page, assign an index id, and store the index descriptor.
 	// Leave the root pointer null for the time being.
 	WIN window(relation->rel_index_root);
diff --git a/src/jrd/idx.cpp b/src/jrd/idx.cpp
index a536c609e2..0212859b64 100644
--- a/src/jrd/idx.cpp
+++ b/src/jrd/idx.cpp
@@ -193,6 +193,10 @@ void IDX_create_index(
 				 isc_arg_string, ERR_cstring(relation->rel_name), 0);
 	}
 
+	if (!relation->rel_index_root) {
+		get_root_page(tdbb, relation);
+	}
+
 	BTR_reserve_slot(tdbb, relation, transaction, idx);
 
 	if (index_id) {