diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index e4715605a2d..cdc7e43b930 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -4186,7 +4186,7 @@ interval_avg(PG_FUNCTION_ARGS)
 		if (state->pInfcount > 0 && state->nInfcount > 0)
 			ereport(ERROR,
 					(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-					 errmsg("interval out of range.")));
+					 errmsg("interval out of range")));
 
 		result = (Interval *) palloc(sizeof(Interval));
 		if (state->pInfcount > 0)
@@ -4223,7 +4223,7 @@ interval_sum(PG_FUNCTION_ARGS)
 	if (state->pInfcount > 0 && state->nInfcount > 0)
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-				 errmsg("interval out of range.")));
+				 errmsg("interval out of range")));
 
 	result = (Interval *) palloc(sizeof(Interval));
 
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index ae4e8851f8a..8b447aa01e5 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -4833,7 +4833,7 @@ FROM (VALUES (NULL::interval),
                ('infinity'::timestamptz - now()),
                ('6 days'::interval),
                ('-infinity'::interval)) v(x);
-ERROR:  interval out of range.
+ERROR:  interval out of range
 --should fail.
 SELECT x, sum(x) OVER(ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING)
 FROM (VALUES (NULL::interval),
@@ -4841,7 +4841,7 @@ FROM (VALUES (NULL::interval),
                ('infinity'::timestamptz - now()),
                ('6 days'::interval),
                ('-infinity'::interval)) v(x);
-ERROR:  interval out of range.
+ERROR:  interval out of range
 SELECT i,SUM(v::smallint) OVER (ORDER BY i ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   FROM (VALUES(1,1),(2,2),(3,NULL),(4,NULL)) t(i,v);
  i | sum