diff --git a/expected/pg_rational_test.out b/expected/pg_rational_test.out
index 73ba945..2c51079 100644
--- a/expected/pg_rational_test.out
+++ b/expected/pg_rational_test.out
@@ -688,3 +688,8 @@ select rational_intermediate(NULL, '15/16');
  1/2
 (1 row)
 
+-- test timeout
+set statement_timeout = '3s';
+select rational_intermediate('2147483646/2147483647'::rational, '1/1'::rational);
+ERROR:  canceling statement due to statement timeout
+set statement_timeout to default;
diff --git a/pg_rational.c b/pg_rational.c
index 4057b5a..c4d8f0d 100644
--- a/pg_rational.c
+++ b/pg_rational.c
@@ -2,6 +2,7 @@
 #include "fmgr.h"
 #include "access/hash.h"
 #include "libpq/pqformat.h"		/* send/recv functions */
+#include "miscadmin.h"
 
 #if PG_VERSION_NUM >= 110000
 #include "common/int.h"			/* portable overflow detection */
@@ -379,6 +380,9 @@ rational_intermediate(PG_FUNCTION_ARGS)
 
 	while (true)
 	{
+		/* Allow query cancel (e.g. Ctrl+C) and statement_timeout . */
+		CHECK_FOR_INTERRUPTS();
+
 		mediant(&lo, &hi, med);
 		if (cmp(med, &x) < 1)
 			memcpy(&lo, med, sizeof(Rational));
diff --git a/sql/pg_rational_test.sql b/sql/pg_rational_test.sql
index c6359db..b45d3d7 100644
--- a/sql/pg_rational_test.sql
+++ b/sql/pg_rational_test.sql
@@ -269,3 +269,8 @@ select rational_intermediate('1/3', NULL);
 select rational_intermediate('3/2', NULL);
 -- though not the other direction
 select rational_intermediate(NULL, '15/16');
+
+-- test timeout
+set statement_timeout = '3s';
+select rational_intermediate('2147483646/2147483647'::rational, '1/1'::rational);
+set statement_timeout to default;
\ No newline at end of file