diff --git a/bin/Makefile b/bin/Makefile
index 1193e5f..c7226c8 100644
--- a/bin/Makefile
+++ b/bin/Makefile
@@ -22,9 +22,14 @@ PROGRAM = pg_repack
 #
 
 ifeq ($(shell echo $$(($(INTVERSION) >= 901))),1)
-REGRESS = init-extension
+REGRESS := init-extension
 else
-REGRESS = init-legacy
+REGRESS := init-legacy
+endif
+
+# plpgsql not available by default on pg < 9.0
+ifeq ($(shell echo $$(($(INTVERSION) < 900))),1)
+REGRESS += plpgsql
 endif
 
 REGRESS += repack tablespace
diff --git a/bin/expected/plpgsql.out b/bin/expected/plpgsql.out
new file mode 100644
index 0000000..bc028fb
--- /dev/null
+++ b/bin/expected/plpgsql.out
@@ -0,0 +1 @@
+CREATE LANGUAGE plpgsql;
diff --git a/bin/sql/plpgsql.sql b/bin/sql/plpgsql.sql
new file mode 100644
index 0000000..bc028fb
--- /dev/null
+++ b/bin/sql/plpgsql.sql
@@ -0,0 +1 @@
+CREATE LANGUAGE plpgsql;