*** a/src/bin/pg_dump/pg_dump.c
--- b/src/bin/pg_dump/pg_dump.c
***************
*** 3532,3537 **** getAggregates(Archive *fout, int *numAggs)
--- 3532,3538 ----
  	int			i_proargtypes;
  	int			i_rolname;
  	int			i_aggacl;
+ 	int			i_proiargs;
  
  	/* Make sure we are in proper schema */
  	selectSourceSchema(fout, "pg_catalog");
***************
*** 3546,3551 **** getAggregates(Archive *fout, int *numAggs)
--- 3547,3553 ----
  		appendPQExpBuffer(query, "SELECT tableoid, oid, proname AS aggname, "
  						  "pronamespace AS aggnamespace, "
  						  "pronargs, proargtypes, "
+ 						  "%s AS proiargs,"
  						  "(%s proowner) AS rolname, "
  						  "proacl AS aggacl "
  						  "FROM pg_proc p "
***************
*** 3553,3558 **** getAggregates(Archive *fout, int *numAggs)
--- 3555,3561 ----
  						  "pronamespace != "
  						  "(SELECT oid FROM pg_namespace "
  						  "WHERE nspname = 'pg_catalog')",
+ 						  (fout->remoteVersion >= 80400) ? "pg_catalog.pg_get_function_identity_arguments(oid)" : "NULL::text",
  						  username_subquery);
  		if (binary_upgrade && fout->remoteVersion >= 90100)
  			appendPQExpBuffer(query,
***************
*** 3569,3574 **** getAggregates(Archive *fout, int *numAggs)
--- 3572,3578 ----
  						  "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 "
***************
*** 3583,3588 **** getAggregates(Archive *fout, int *numAggs)
--- 3587,3593 ----
  						  "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 "
***************
*** 3598,3603 **** getAggregates(Archive *fout, int *numAggs)
--- 3603,3609 ----
  						  "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 "
***************
*** 3621,3626 **** getAggregates(Archive *fout, int *numAggs)
--- 3627,3633 ----
  	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++)
  	{
***************
*** 3640,3645 **** getAggregates(Archive *fout, int *numAggs)
--- 3647,3653 ----
  		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;
***************
*** 3691,3696 **** getFuncs(Archive *fout, int *numFuncs)
--- 3699,3705 ----
  	int			i_proargtypes;
  	int			i_prorettype;
  	int			i_proacl;
+ 	int			i_proiargs;
  
  	/* Make sure we are in proper schema */
  	selectSourceSchema(fout, "pg_catalog");
***************
*** 3717,3728 **** getFuncs(Archive *fout, int *numFuncs)
--- 3726,3739 ----
  						  "SELECT tableoid, oid, proname, prolang, "
  						  "pronargs, proargtypes, prorettype, proacl, "
  						  "pronamespace, "
+ 						  "%s AS proiargs,"
  						  "(%s proowner) AS rolname "
  						  "FROM pg_proc p "
  						  "WHERE NOT proisagg AND ("
  						  "pronamespace != "
  						  "(SELECT oid FROM pg_namespace "
  						  "WHERE nspname = 'pg_catalog')",
+ 						  (fout->remoteVersion >= 80400) ? "pg_catalog.pg_get_function_identity_arguments(oid)" : "NULL::text",
  						  username_subquery);
  		if (fout->remoteVersion >= 90200)
  			appendPQExpBuffer(query,
***************
*** 3745,3750 **** getFuncs(Archive *fout, int *numFuncs)
--- 3756,3762 ----
  						  "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",
***************
*** 3761,3766 **** getFuncs(Archive *fout, int *numFuncs)
--- 3773,3779 ----
  						  "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",
***************
*** 3786,3791 **** getFuncs(Archive *fout, int *numFuncs)
--- 3799,3805 ----
  	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++)
  	{
***************
*** 3801,3806 **** getFuncs(Archive *fout, int *numFuncs)
--- 3815,3821 ----
  		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
***************
*** 192,197 **** typedef struct _funcInfo
--- 192,198 ----
  	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
***************
*** 194,199 **** DOTypeNameCompare(const void *p1, const void *p2)
--- 194,202 ----
  		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)
  	{