diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 41a0107491b..fdfb4317f4b 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -4199,7 +4199,6 @@ getAggregates(Archive *fout, DumpOptions *dopt, int *numAggs)
 	int			i_proargtypes;
 	int			i_rolname;
 	int			i_aggacl;
-	int			i_proiargs;
 
 	/* Make sure we are in proper schema */
 	selectSourceSchema(fout, "pg_catalog");
@@ -4209,12 +4208,11 @@ getAggregates(Archive *fout, DumpOptions *dopt, int *numAggs)
 	 * rationale behind the filtering logic.
 	 */
 
-	if (fout->remoteVersion >= 80400)
+	if (fout->remoteVersion >= 80200)
 	{
 		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 "
@@ -4232,28 +4230,12 @@ getAggregates(Archive *fout, DumpOptions *dopt, int *numAggs)
 								 "deptype = 'e')");
 		appendPQExpBufferChar(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 "
-						  "WHERE proisagg AND ("
-						  "pronamespace != "
-						  "(SELECT oid FROM pg_namespace "
-						  "WHERE nspname = 'pg_catalog'))",
-						  username_subquery);
-	}
 	else if (fout->remoteVersion >= 70300)
 	{
 		appendPQExpBuffer(query, "SELECT tableoid, oid, proname AS aggname, "
 						  "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 "
@@ -4268,7 +4250,6 @@ getAggregates(Archive *fout, DumpOptions *dopt, int *numAggs)
 						  "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 "
@@ -4284,7 +4265,6 @@ getAggregates(Archive *fout, DumpOptions *dopt, int *numAggs)
 						  "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 "
@@ -4308,7 +4288,6 @@ getAggregates(Archive *fout, DumpOptions *dopt, int *numAggs)
 	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++)
 	{
@@ -4328,7 +4307,6 @@ getAggregates(Archive *fout, DumpOptions *dopt, int *numAggs)
 		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;
@@ -4380,7 +4358,6 @@ getFuncs(Archive *fout, DumpOptions *dopt, int *numFuncs)
 	int			i_proargtypes;
 	int			i_prorettype;
 	int			i_proacl;
-	int			i_proiargs;
 
 	/* Make sure we are in proper schema */
 	selectSourceSchema(fout, "pg_catalog");
@@ -4401,13 +4378,12 @@ getFuncs(Archive *fout, DumpOptions *dopt, int *numFuncs)
 	 * doesn't have; otherwise we might not get creation ordering correct.
 	 */
 
-	if (fout->remoteVersion >= 80400)
+	if (fout->remoteVersion >= 70300)
 	{
 		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 ("
@@ -4429,21 +4405,6 @@ getFuncs(Archive *fout, DumpOptions *dopt, int *numFuncs)
 								 "deptype = 'e')");
 		appendPQExpBufferChar(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 ("
-						  "pronamespace != "
-						  "(SELECT oid FROM pg_namespace "
-						  "WHERE nspname = 'pg_catalog'))",
-						  username_subquery);
-	}
 	else if (fout->remoteVersion >= 70100)
 	{
 		appendPQExpBuffer(query,
@@ -4451,7 +4412,6 @@ getFuncs(Archive *fout, DumpOptions *dopt, int *numFuncs)
 						  "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",
@@ -4468,7 +4428,6 @@ getFuncs(Archive *fout, DumpOptions *dopt, int *numFuncs)
 						  "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",
@@ -4494,7 +4453,6 @@ getFuncs(Archive *fout, DumpOptions *dopt, int *numFuncs)
 	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++)
 	{
@@ -4510,7 +4468,6 @@ getFuncs(Archive *fout, DumpOptions *dopt, int *numFuncs)
 		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)
diff --git a/src/bin/pg_dump/pg_dump.h b/src/bin/pg_dump/pg_dump.h
index f42c42d5e6a..a9d3c1016be 100644
--- a/src/bin/pg_dump/pg_dump.h
+++ b/src/bin/pg_dump/pg_dump.h
@@ -149,7 +149,6 @@ typedef struct _funcInfo
 	Oid		   *argtypes;
 	Oid			prorettype;
 	char	   *proacl;
-	char	   *proiargs;
 } FuncInfo;
 
 /* AggInfo is a superset of FuncInfo */
diff --git a/src/bin/pg_dump/pg_dump_sort.c b/src/bin/pg_dump/pg_dump_sort.c
index 4b9bba07237..c5ed593e02e 100644
--- a/src/bin/pg_dump/pg_dump_sort.c
+++ b/src/bin/pg_dump/pg_dump_sort.c
@@ -291,13 +291,30 @@ DOTypeNameCompare(const void *p1, const void *p2)
 	{
 		FuncInfo   *fobj1 = *(FuncInfo *const *) p1;
 		FuncInfo   *fobj2 = *(FuncInfo *const *) p2;
+		int			i;
 
 		cmpval = fobj1->nargs - fobj2->nargs;
 		if (cmpval != 0)
 			return cmpval;
-		cmpval = strcmp(fobj1->proiargs, fobj2->proiargs);
-		if (cmpval != 0)
-			return cmpval;
+		for (i = 0; i < fobj1->nargs; i++)
+		{
+			TypeInfo   *argtype1 = findTypeByOid(fobj1->argtypes[i]);
+			TypeInfo   *argtype2 = findTypeByOid(fobj2->argtypes[i]);
+
+			if (argtype1 && argtype2)
+			{
+				if (argtype1->dobj.namespace && argtype2->dobj.namespace)
+				{
+					cmpval = strcmp(argtype1->dobj.namespace->dobj.name,
+									argtype2->dobj.namespace->dobj.name);
+					if (cmpval != 0)
+						return cmpval;
+				}
+				cmpval = strcmp(argtype1->dobj.name, argtype2->dobj.name);
+				if (cmpval != 0)
+					return cmpval;
+			}
+		}
 	}
 	else if (obj1->objType == DO_OPERATOR)
 	{