diff -Nru postgresql-periods-1.2/debian/changelog postgresql-periods-1.2/debian/changelog
--- postgresql-periods-1.2/debian/changelog	2020-10-19 13:39:38.000000000 +0000
+++ postgresql-periods-1.2/debian/changelog	2020-11-06 12:27:51.000000000 +0000
@@ -1,3 +1,9 @@
+postgresql-periods (1.2-3) unstable; urgency=medium
+
+  * Depend on postgresql-contrib-PGVERSION for btree_gist on 9.x.
+
+ -- Christoph Berg <myon@debian.org>  Fri, 06 Nov 2020 13:27:51 +0100
+
 postgresql-periods (1.2-2) unstable; urgency=medium
 
   * Upload for PostgreSQL 13.
diff -Nru postgresql-periods-1.2/debian/control postgresql-periods-1.2/debian/control
--- postgresql-periods-1.2/debian/control	2020-10-19 13:39:38.000000000 +0000
+++ postgresql-periods-1.2/debian/control	2020-11-06 12:27:51.000000000 +0000
@@ -12,7 +12,7 @@
 
 Package: postgresql-13-periods
 Architecture: any
-Depends: postgresql-13, ${misc:Depends}, ${shlibs:Depends}
+Depends: postgresql-13, postgresql-contrib-13, ${misc:Depends}, ${shlibs:Depends}
 Description: PERIODs and SYSTEM VERSIONING for PostgreSQL
  This extension attempts to recreate the behavior defined in SQL:2016
  (originally SQL:2011) around periods and tables with SYSTEM VERSIONING. The
diff -Nru postgresql-periods-1.2/debian/control.in postgresql-periods-1.2/debian/control.in
--- postgresql-periods-1.2/debian/control.in	2020-10-19 13:39:38.000000000 +0000
+++ postgresql-periods-1.2/debian/control.in	2020-11-06 12:27:50.000000000 +0000
@@ -12,7 +12,7 @@
 
 Package: postgresql-PGVERSION-periods
 Architecture: any
-Depends: postgresql-PGVERSION, ${misc:Depends}, ${shlibs:Depends}
+Depends: postgresql-PGVERSION, postgresql-contrib-PGVERSION, ${misc:Depends}, ${shlibs:Depends}
 Description: PERIODs and SYSTEM VERSIONING for PostgreSQL
  This extension attempts to recreate the behavior defined in SQL:2016
  (originally SQL:2011) around periods and tables with SYSTEM VERSIONING. The