diff --git a/src/backend/access/brin/brin_minmax_multi.c b/src/backend/access/brin/brin_minmax_multi.c
index f8b2a3f9bc..8c72a0a036 100644
--- a/src/backend/access/brin/brin_minmax_multi.c
+++ b/src/backend/access/brin/brin_minmax_multi.c
@@ -2144,7 +2144,7 @@ brin_minmax_multi_distance_timestamp(PG_FUNCTION_ARGS)
 	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
 		PG_RETURN_FLOAT8(0);
 
-	delta = dt2 - dt1;
+	delta = (float8) dt2 - (float8) dt1;
 
 	Assert(delta >= 0);
 
diff --git a/src/test/regress/expected/brin_multi.out b/src/test/regress/expected/brin_multi.out
index 9f46934c9b..c18d9764c1 100644
--- a/src/test/regress/expected/brin_multi.out
+++ b/src/test/regress/expected/brin_multi.out
@@ -823,3 +823,18 @@ SELECT COUNT(*) FROM brin_test_multi_2 WHERE a = 'aab32389-22bc-c25a-6f60-6eb525
 
 DROP TABLE brin_test_multi_2;
 RESET enable_seqscan;
+-- test overflows during CREATE INDEX with extreme timestamp values
+CREATE TABLE brin_timestamp_test(a TIMESTAMPTZ);
+SET datestyle TO iso;
+-- values close to timetamp minimum
+INSERT INTO brin_timestamp_test
+SELECT '4713-01-01 00:00:01 BC'::timestamptz + (i || ' seconds')::interval
+  FROM generate_series(1,30) s(i);
+-- values close to timetamp maximum
+INSERT INTO brin_timestamp_test
+SELECT '294276-12-01 00:00:01'::timestamptz + (i || ' seconds')::interval
+  FROM generate_series(1,30) s(i);
+CREATE INDEX ON brin_timestamp_test USING brin (a timestamptz_minmax_multi_ops) WITH (pages_per_range=1);
+DROP TABLE brin_timestamp_test;
+RESET enable_seqscan;
+RESET datestyle;
diff --git a/src/test/regress/sql/brin_multi.sql b/src/test/regress/sql/brin_multi.sql
index d50dbdee68..847bb5aa01 100644
--- a/src/test/regress/sql/brin_multi.sql
+++ b/src/test/regress/sql/brin_multi.sql
@@ -586,3 +586,24 @@ SELECT COUNT(*) FROM brin_test_multi_2 WHERE a = 'aab32389-22bc-c25a-6f60-6eb525
 
 DROP TABLE brin_test_multi_2;
 RESET enable_seqscan;
+
+-- test overflows during CREATE INDEX with extreme timestamp values
+CREATE TABLE brin_timestamp_test(a TIMESTAMPTZ);
+
+SET datestyle TO iso;
+
+-- values close to timetamp minimum
+INSERT INTO brin_timestamp_test
+SELECT '4713-01-01 00:00:01 BC'::timestamptz + (i || ' seconds')::interval
+  FROM generate_series(1,30) s(i);
+
+-- values close to timetamp maximum
+INSERT INTO brin_timestamp_test
+SELECT '294276-12-01 00:00:01'::timestamptz + (i || ' seconds')::interval
+  FROM generate_series(1,30) s(i);
+
+CREATE INDEX ON brin_timestamp_test USING brin (a timestamptz_minmax_multi_ops) WITH (pages_per_range=1);
+DROP TABLE brin_timestamp_test;
+
+RESET enable_seqscan;
+RESET datestyle;