diff --git a/Makefile b/Makefile
index 1e43714..d74c55a 100644
--- a/Makefile
+++ b/Makefile
@@ -6,18 +6,18 @@
 #  Portions Copyright (c) 2012, The Reorg Development Team
 #
 
-USE_PGXS = 1
-PG_CONFIG = pg_config
-PGXS := $(shell $(PG_CONFIG) --pgxs)
-include $(PGXS)
+PG_CONFIG ?= pg_config
 
 SUBDIRS = bin lib
 
 # Pull out the version number from pg_config
-VERSION = $(shell $(PG_CONFIG) --version | awk '{print $$2}')
+VERSION := $(shell $(PG_CONFIG) --version | awk '{print $$2}')
+
+# version as a number, e.g. 9.1.4 -> 90104
+INTVERSION := $(shell echo $(VERSION) | sed -E 's/([0-9]+)\.([0-9]+)\.?([0-9]+)?(.*)/(\1*100+\2)*100+0\3/' | bc)
 
 # We support PostgreSQL 8.3 and later.
-ifneq ($(shell echo $(VERSION) | grep -E "^7\.|^8\.[012]"),)
+ifeq ($(shell echo $$(($(INTVERSION) < 80300))),1)
 $(error pg_repack requires PostgreSQL 8.3 or later. This is $(VERSION))
 endif
 
diff --git a/bin/Makefile b/bin/Makefile
index 24ae1cd..d871e30 100644
--- a/bin/Makefile
+++ b/bin/Makefile
@@ -5,12 +5,24 @@
 #  Portions Copyright (c) 2011, Itagaki Takahiro
 #  Portions Copyright (c) 2012, The Reorg Development Team
 #
+
+PG_CONFIG ?= pg_config
+
+# version as a number, e.g. 9.1.4 -> 90104
+VERSION := $(shell $(PG_CONFIG) --version | awk '{print $$2}')
+INTVERSION := $(shell echo $(VERSION) | sed -E 's/([0-9]+)\.([0-9]+)\.?([0-9]+)?.*/(\1*100+\2)*100+0\3/' | bc)
+
 SRCS = pg_repack.c pgut/pgut.c pgut/pgut-fe.c
 OBJS = $(SRCS:.c=.o)
 PROGRAM = pg_repack
-REGRESS = init repack tablespace
 
-EXTRA_CLEAN = sql/init-$(MAJORVERSION).sql sql/init.sql
+ifeq ($(shell echo $$(($(INTVERSION) >= 90100))),1)
+REGRESS = init-extension
+else
+REGRESS = init-legacy
+endif
+
+REGRESS += repack tablespace
 
 # The version number of the program. It should be the same of the library.
 REPACK_VERSION = $(shell grep '"version":' ../META.json | head -1 \
@@ -33,25 +45,3 @@ include $(PGXS)
 LIBS := $(filter-out -lxml2, $(LIBS))
 LIBS := $(filter-out -lxslt, $(LIBS))
 
-ifndef MAJORVERSION
-MAJORVERSION := $(basename $(VERSION))
-endif
-
-sql/init.sql: sql/init-$(MAJORVERSION).sql
-	cp sql/init-$(MAJORVERSION).sql sql/init.sql
-expected/init.out: expected/init-$(MAJORVERSION).out
-	cp expected/init-$(MAJORVERSION).out expected/init.out
-sql/init-8.3.sql:
-	cp sql/init-legacy.sql sql/init-8.3.sql
-sql/init-8.4.sql:
-	cp sql/init-legacy.sql sql/init-8.4.sql
-sql/init-9.0.sql:
-	cp sql/init-legacy.sql sql/init-9.0.sql
-sql/init-9.1.sql:
-	cp sql/init-extension.sql sql/init-9.1.sql
-sql/init-9.2.sql:
-	cp sql/init-extension.sql sql/init-9.2.sql
-sql/init-9.3.sql:
-	cp sql/init-extension.sql sql/init-9.3.sql
-
-installcheck: sql/init.sql
diff --git a/bin/expected/init-extension.out b/bin/expected/init-extension.out
new file mode 100644
index 0000000..9f2e171
--- /dev/null
+++ b/bin/expected/init-extension.out
@@ -0,0 +1,3 @@
+SET client_min_messages = warning;
+CREATE EXTENSION pg_repack;
+RESET client_min_messages;
diff --git a/bin/expected/init.out b/bin/expected/init-legacy.out
similarity index 100%
rename from bin/expected/init.out
rename to bin/expected/init-legacy.out
diff --git a/bin/sql/init-extension.sql b/bin/sql/init-extension.sql
index 9da3176..9f2e171 100644
--- a/bin/sql/init-extension.sql
+++ b/bin/sql/init-extension.sql
@@ -1,5 +1,3 @@
 SET client_min_messages = warning;
-\set ECHO none
 CREATE EXTENSION pg_repack;
-\set ECHO all
 RESET client_min_messages;
diff --git a/lib/Makefile b/lib/Makefile
index ca38f3a..8698163 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -6,7 +6,11 @@
 #  Portions Copyright (c) 2012, The Reorg Development Team
 #
 
-PG_CONFIG = pg_config
+PG_CONFIG ?= pg_config
+
+# version as a number, e.g. 9.1.4 -> 90104
+VERSION := $(shell $(PG_CONFIG) --version | awk '{print $$2}')
+INTVERSION := $(shell echo $(VERSION) | sed -E 's/([0-9]+)\.([0-9]+)\.?([0-9]+)?.*/(\1*100+\2)*100+0\3/' | bc)
 
 EXTENSION = pg_repack
 MODULE_big = $(EXTENSION)
@@ -20,10 +24,7 @@ REPACK_VERSION = $(shell grep '"version":' ../META.json | head -1 \
 PG_CPPFLAGS = -DREPACK_VERSION=$(REPACK_VERSION)
 
 # Support CREATE EXTENSION for PG >= 9.1 and a simple sql script for PG < 9.1
-HAVE_EXTENSION = $(shell $(PG_CONFIG) --version \
-	| grep -qE " 8\.| 9\.0" && echo no || echo yes)
-
-ifeq ($(HAVE_EXTENSION),yes)
+ifeq ($(shell echo $$(($(INTVERSION) >= 90100))),1)
 DATA_built = pg_repack--$(REPACK_VERSION).sql pg_repack.control
 else
 DATA_built = pg_repack.sql