diff --git a/Makefile b/Makefile
index 17bdd4a9..c034e40f 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@
 #
 
 MODULES = pg_hint_plan
-HINTPLANVER = 1.5.1
+HINTPLANVER = 1.5
 
 REGRESS = init base_plan pg_hint_plan ut-init ut-A ut-S ut-J ut-L ut-G ut-R \
 	ut-fdw ut-W ut-T ut-fini hints_anywhere plpgsql oldextversions
@@ -24,8 +24,7 @@ DATA = \
 	pg_hint_plan--1.3.7--1.3.8.sql \
 	pg_hint_plan--1.3.8--1.4.sql \
 	pg_hint_plan--1.4--1.4.1.sql \
-	pg_hint_plan--1.4.1--1.5.sql \
-	pg_hint_plan--1.5--1.5.1.sql
+	pg_hint_plan--1.4.1--1.5.sql
 
 EXTRA_CLEAN = RPMS
 
diff --git a/SPECS/pg_hint_plan15.spec b/SPECS/pg_hint_plan15.spec
index 140f0d25..f337b410 100644
--- a/SPECS/pg_hint_plan15.spec
+++ b/SPECS/pg_hint_plan15.spec
@@ -16,7 +16,7 @@
 ## Set general information for pg_store_plans.
 Summary:    Optimizer hint on PostgreSQL 15
 Name:       pg_hint_plan15
-Version:    1.5.1
+Version:    1.5
 Release:    1%{?dist}
 License:    BSD
 Group:      Applications/Databases
@@ -39,7 +39,7 @@ Note that this package is available for only PostgreSQL 15.
 
 %package llvmjit
 Requires: postgresql15-server, postgresql15-llvmjit
-Requires: pg_hint_plan15 = 1.5.1
+Requires: pg_hint_plan15 = 1.5
 Summary:  Just-in-time compilation support for pg_hint_plan15
 
 %description llvmjit
@@ -85,7 +85,6 @@ rm -rf %{buildroot}
 %{_datadir}/extension/pg_hint_plan--1.3.8--1.4.sql
 %{_datadir}/extension/pg_hint_plan--1.4--1.4.1.sql
 %{_datadir}/extension/pg_hint_plan--1.4.1--1.5.sql
-%{_datadir}/extension/pg_hint_plan--1.5--1.5.1.sql
 %{_datadir}/extension/pg_hint_plan.control
 
 %files llvmjit
@@ -98,6 +97,6 @@ rm -rf %{buildroot}
 # History of pg_hint_plan.
 %changelog
 * Fri Jan 20 2023 Michael Paquier
-- Version 1.5.1.
+- Version 1.5.0.
 * Thu Sep 29 2022 Masahiro Ikeda
 - Support PostgreSQL 15.
diff --git a/expected/oldextversions.out b/expected/oldextversions.out
index 0b97c8c8..fdf2afae 100644
--- a/expected/oldextversions.out
+++ b/expected/oldextversions.out
@@ -109,13 +109,4 @@ Objects in extension "pg_hint_plan"
  table hint_plan.hints
 (2 rows)
 
-ALTER EXTENSION pg_hint_plan UPDATE TO "1.5.1";
-\dx+ pg_hint_plan
-Objects in extension "pg_hint_plan"
-       Object description        
----------------------------------
- sequence hint_plan.hints_id_seq
- table hint_plan.hints
-(2 rows)
-
 DROP EXTENSION pg_hint_plan;
diff --git a/pg_hint_plan--1.5--1.5.1.sql b/pg_hint_plan--1.5--1.5.1.sql
deleted file mode 100644
index 14d7379a..00000000
--- a/pg_hint_plan--1.5--1.5.1.sql
+++ /dev/null
@@ -1,10 +0,0 @@
-/* pg_hint_plan/pg_hint_plan--1.5--1.5.1.sql */
-
--- complain if script is sourced in psql, rather than via CREATE EXTENSION
-\echo Use "ALTER EXTENSION pg_dbms_stats UPDATE TO '1.5.1'" to load this file. \quit
-
-SELECT pg_catalog.pg_extension_config_dump('hint_plan.hints','');
-SELECT pg_catalog.pg_extension_config_dump('hint_plan.hints_id_seq','');
-
-GRANT SELECT ON hint_plan.hints TO PUBLIC;
-GRANT USAGE ON SCHEMA hint_plan TO PUBLIC;
diff --git a/pg_hint_plan.control b/pg_hint_plan.control
index 94682c34..1b7ede8f 100644
--- a/pg_hint_plan.control
+++ b/pg_hint_plan.control
@@ -1,6 +1,6 @@
 # pg_hint_plan extension
 
 comment = ''
-default_version = '1.5.1'
+default_version = '1.5'
 relocatable = false
 schema = hint_plan
diff --git a/sql/oldextversions.sql b/sql/oldextversions.sql
index cee6ec4e..d7863127 100644
--- a/sql/oldextversions.sql
+++ b/sql/oldextversions.sql
@@ -26,6 +26,4 @@ ALTER EXTENSION pg_hint_plan UPDATE TO "1.4.1";
 \dx+ pg_hint_plan
 ALTER EXTENSION pg_hint_plan UPDATE TO "1.5";
 \dx+ pg_hint_plan
-ALTER EXTENSION pg_hint_plan UPDATE TO "1.5.1";
-\dx+ pg_hint_plan
 DROP EXTENSION pg_hint_plan;