*** a/src/bin/pg_dump/pg_dump.c
--- b/src/bin/pg_dump/pg_dump.c
***************
*** 3534,3539 **** getAggregates(Archive *fout, int *numAggs)
--- 3534,3540 ----
  	int			i_proargtypes;
  	int			i_rolname;
  	int			i_aggacl;
+ 	int			i_proiargs;
  
  	/* Make sure we are in proper schema */
  	selectSourceSchema(fout, "pg_catalog");
***************
*** 3543,3553 **** getAggregates(Archive *fout, int *numAggs)
  	 * rationale behind the filtering logic.
  	 */
  
! 	if (fout->remoteVersion >= 80200)
  	{
  		appendPQExpBuffer(query, "SELECT tableoid, oid, proname AS aggname, "
  						  "pronamespace AS aggnamespace, "
  						  "pronargs, proargtypes, "
  						  "(%s proowner) AS rolname, "
  						  "proacl AS aggacl "
  						  "FROM pg_proc p "
--- 3544,3578 ----
  	 * rationale behind the filtering logic.
  	 */
  
! 	if (fout->remoteVersion >= 80400)
  	{
  		appendPQExpBuffer(query, "SELECT tableoid, oid, proname AS aggname, "
  						  "pronamespace AS aggnamespace, "
  						  "pronargs, proargtypes, "
+ 						  "pg_catalog.pg_get_function_identity_arguments(oid) AS proiargs,"
+ 						  "(%s proowner) AS rolname, "
+ 						  "proacl AS aggacl "
+ 						  "FROM pg_proc p "
+ 						  "WHERE proisagg AND ("
+ 						  "pronamespace != "
+ 						  "(SELECT oid FROM pg_namespace "
+ 						  "WHERE nspname = 'pg_catalog')",
+ 						  username_subquery);
+ 		if (binary_upgrade && fout->remoteVersion >= 90100)
+ 			appendPQExpBuffer(query,
+ 							  " OR EXISTS(SELECT 1 FROM pg_depend WHERE "
+ 							  "classid = 'pg_proc'::regclass AND "
+ 							  "objid = p.oid AND "
+ 							  "refclassid = 'pg_extension'::regclass AND "
+ 							  "deptype = 'e')");
+ 		appendPQExpBuffer(query, ")");
+ 	}
+ 	else if (fout->remoteVersion >= 80200)
+ 	{
+ 		appendPQExpBuffer(query, "SELECT tableoid, oid, proname AS aggname, "
+ 						  "pronamespace AS aggnamespace, "
+ 						  "pronargs, proargtypes, "
+ 						  "NULL::text AS proiargs,"
  						  "(%s proowner) AS rolname, "
  						  "proacl AS aggacl "
  						  "FROM pg_proc p "
***************
*** 3571,3576 **** getAggregates(Archive *fout, int *numAggs)
--- 3596,3602 ----
  						  "pronamespace AS aggnamespace, "
  						  "CASE WHEN proargtypes[0] = 'pg_catalog.\"any\"'::pg_catalog.regtype THEN 0 ELSE 1 END AS pronargs, "
  						  "proargtypes, "
+ 						  "NULL::text AS proiargs, "
  						  "(%s proowner) AS rolname, "
  						  "proacl AS aggacl "
  						  "FROM pg_proc "
***************
*** 3585,3590 **** getAggregates(Archive *fout, int *numAggs)
--- 3611,3617 ----
  						  "0::oid AS aggnamespace, "
  				  "CASE WHEN aggbasetype = 0 THEN 0 ELSE 1 END AS pronargs, "
  						  "aggbasetype AS proargtypes, "
+ 						  "NULL::text AS proiargs, "
  						  "(%s aggowner) AS rolname, "
  						  "'{=X}' AS aggacl "
  						  "FROM pg_aggregate "
***************
*** 3600,3605 **** getAggregates(Archive *fout, int *numAggs)
--- 3627,3633 ----
  						  "0::oid AS aggnamespace, "
  				  "CASE WHEN aggbasetype = 0 THEN 0 ELSE 1 END AS pronargs, "
  						  "aggbasetype AS proargtypes, "
+ 						  "NULL::text AS proiargs, "
  						  "(%s aggowner) AS rolname, "
  						  "'{=X}' AS aggacl "
  						  "FROM pg_aggregate "
***************
*** 3623,3628 **** getAggregates(Archive *fout, int *numAggs)
--- 3651,3657 ----
  	i_proargtypes = PQfnumber(res, "proargtypes");
  	i_rolname = PQfnumber(res, "rolname");
  	i_aggacl = PQfnumber(res, "aggacl");
+ 	i_proiargs = PQfnumber(res, "proiargs");
  
  	for (i = 0; i < ntups; i++)
  	{
***************
*** 3642,3647 **** getAggregates(Archive *fout, int *numAggs)
--- 3671,3677 ----
  		agginfo[i].aggfn.lang = InvalidOid;		/* not currently interesting */
  		agginfo[i].aggfn.prorettype = InvalidOid;		/* not saved */
  		agginfo[i].aggfn.proacl = pg_strdup(PQgetvalue(res, i, i_aggacl));
+ 		agginfo[i].aggfn.proiargs = pg_strdup(PQgetvalue(res, i, i_proiargs));
  		agginfo[i].aggfn.nargs = atoi(PQgetvalue(res, i, i_pronargs));
  		if (agginfo[i].aggfn.nargs == 0)
  			agginfo[i].aggfn.argtypes = NULL;
***************
*** 3693,3698 **** getFuncs(Archive *fout, int *numFuncs)
--- 3723,3729 ----
  	int			i_proargtypes;
  	int			i_prorettype;
  	int			i_proacl;
+ 	int			i_proiargs;
  
  	/* Make sure we are in proper schema */
  	selectSourceSchema(fout, "pg_catalog");
***************
*** 3713,3724 **** getFuncs(Archive *fout, int *numFuncs)
  	 * doesn't have; otherwise we might not get creation ordering correct.
  	 */
  
! 	if (fout->remoteVersion >= 70300)
  	{
  		appendPQExpBuffer(query,
  						  "SELECT tableoid, oid, proname, prolang, "
  						  "pronargs, proargtypes, prorettype, proacl, "
  						  "pronamespace, "
  						  "(%s proowner) AS rolname "
  						  "FROM pg_proc p "
  						  "WHERE NOT proisagg AND ("
--- 3744,3784 ----
  	 * doesn't have; otherwise we might not get creation ordering correct.
  	 */
  
! 	if (fout->remoteVersion >= 80400)
! 	{
! 		appendPQExpBuffer(query,
! 						  "SELECT tableoid, oid, proname, prolang, "
! 						  "pronargs, proargtypes, prorettype, proacl, "
! 						  "pronamespace, "
! 						  "pg_catalog.pg_get_function_identity_arguments(oid) AS proiargs,"
! 						  "(%s proowner) AS rolname "
! 						  "FROM pg_proc p "
! 						  "WHERE NOT proisagg AND ("
! 						  "pronamespace != "
! 						  "(SELECT oid FROM pg_namespace "
! 						  "WHERE nspname = 'pg_catalog')",
! 						  username_subquery);
! 		if (fout->remoteVersion >= 90200)
! 			appendPQExpBuffer(query,
! 							  "\n  AND NOT EXISTS (SELECT 1 FROM pg_depend "
! 							  "WHERE classid = 'pg_proc'::regclass AND "
! 							  "objid = p.oid AND deptype = 'i')");
! 		if (binary_upgrade && fout->remoteVersion >= 90100)
! 			appendPQExpBuffer(query,
! 							  "\n  OR EXISTS(SELECT 1 FROM pg_depend WHERE "
! 							  "classid = 'pg_proc'::regclass AND "
! 							  "objid = p.oid AND "
! 							  "refclassid = 'pg_extension'::regclass AND "
! 							  "deptype = 'e')");
! 		appendPQExpBuffer(query, ")");
! 	}
! 	else if (fout->remoteVersion >= 70300)
  	{
  		appendPQExpBuffer(query,
  						  "SELECT tableoid, oid, proname, prolang, "
  						  "pronargs, proargtypes, prorettype, proacl, "
  						  "pronamespace, "
+ 						  "NULL::text AS proiargs,"
  						  "(%s proowner) AS rolname "
  						  "FROM pg_proc p "
  						  "WHERE NOT proisagg AND ("
***************
*** 3747,3752 **** getFuncs(Archive *fout, int *numFuncs)
--- 3807,3813 ----
  						  "pronargs, proargtypes, prorettype, "
  						  "'{=X}' AS proacl, "
  						  "0::oid AS pronamespace, "
+ 						  "NULL::text AS proiargs,"
  						  "(%s proowner) AS rolname "
  						  "FROM pg_proc "
  						  "WHERE pg_proc.oid > '%u'::oid",
***************
*** 3763,3768 **** getFuncs(Archive *fout, int *numFuncs)
--- 3824,3830 ----
  						  "pronargs, proargtypes, prorettype, "
  						  "'{=X}' AS proacl, "
  						  "0::oid AS pronamespace, "
+ 						  "NULL::text AS proiargs,"
  						  "(%s proowner) AS rolname "
  						  "FROM pg_proc "
  						  "where pg_proc.oid > '%u'::oid",
***************
*** 3788,3793 **** getFuncs(Archive *fout, int *numFuncs)
--- 3850,3856 ----
  	i_proargtypes = PQfnumber(res, "proargtypes");
  	i_prorettype = PQfnumber(res, "prorettype");
  	i_proacl = PQfnumber(res, "proacl");
+ 	i_proiargs = PQfnumber(res, "proiargs");
  
  	for (i = 0; i < ntups; i++)
  	{
***************
*** 3803,3808 **** getFuncs(Archive *fout, int *numFuncs)
--- 3866,3872 ----
  		finfo[i].rolname = pg_strdup(PQgetvalue(res, i, i_rolname));
  		finfo[i].lang = atooid(PQgetvalue(res, i, i_prolang));
  		finfo[i].prorettype = atooid(PQgetvalue(res, i, i_prorettype));
+ 		finfo[i].proiargs = pg_strdup(PQgetvalue(res, i, i_proiargs));
  		finfo[i].proacl = pg_strdup(PQgetvalue(res, i, i_proacl));
  		finfo[i].nargs = atoi(PQgetvalue(res, i, i_pronargs));
  		if (finfo[i].nargs == 0)
*** a/src/bin/pg_dump/pg_dump.h
--- b/src/bin/pg_dump/pg_dump.h
***************
*** 193,198 **** typedef struct _funcInfo
--- 193,199 ----
  	Oid		   *argtypes;
  	Oid			prorettype;
  	char	   *proacl;
+ 	char	   *proiargs;
  } FuncInfo;
  
  /* AggInfo is a superset of FuncInfo */
*** a/src/bin/pg_dump/pg_dump_sort.c
--- b/src/bin/pg_dump/pg_dump_sort.c
***************
*** 198,203 **** DOTypeNameCompare(const void *p1, const void *p2)
--- 198,206 ----
  		cmpval = fobj1->nargs - fobj2->nargs;
  		if (cmpval != 0)
  			return cmpval;
+ 		cmpval = strcmp(fobj1->proiargs, fobj2->proiargs);
+ 		if (cmpval != 0)
+ 			return cmpval;
  	}
  	else if (obj1->objType == DO_OPERATOR)
  	{