diff -ruN postgresql-7.4.5-old/src/backend/commands/conversioncmds.c postgresql-7.4.5/src/backend/commands/conversioncmds.c
--- postgresql-7.4.5-old/src/backend/commands/conversioncmds.c	2003-08-04 04:39:58.000000000 +0200
+++ postgresql-7.4.5/src/backend/commands/conversioncmds.c	2005-05-04 12:49:46.654168712 +0200
@@ -46,7 +46,7 @@
 	const char *from_encoding_name = stmt->for_encoding_name;
 	const char *to_encoding_name = stmt->to_encoding_name;
 	List	   *func_name = stmt->func_name;
-	static Oid	funcargs[] = {INT4OID, INT4OID, CSTRINGOID, CSTRINGOID, INT4OID};
+	static Oid	funcargs[] = {INT4OID, INT4OID, CSTRINGOID, INTERNALOID, INT4OID};
 
 	/* Convert list of names to a name and namespace */
 	namespaceId = QualifiedNameGetCreationNamespace(stmt->conversion_name,
diff -ruN postgresql-7.4.5-old/src/backend/utils/mb/conversion_procs/Makefile postgresql-7.4.5/src/backend/utils/mb/conversion_procs/Makefile
--- postgresql-7.4.5-old/src/backend/utils/mb/conversion_procs/Makefile	2004-01-21 20:25:11.000000000 +0100
+++ postgresql-7.4.5/src/backend/utils/mb/conversion_procs/Makefile	2005-05-04 12:49:46.671166128 +0200
@@ -157,7 +157,7 @@
 		func=$$1; shift; \
 		obj=$$1; shift; \
 		echo "-- $$se --> $$de"; \
-		echo "CREATE OR REPLACE FUNCTION $$func (INTEGER, INTEGER, CSTRING, CSTRING, INTEGER) RETURNS VOID AS '$$"libdir"/$$obj', '$$func' LANGUAGE 'c' STRICT;"; \
+		echo "CREATE OR REPLACE FUNCTION $$func (INTEGER, INTEGER, CSTRING, INTERNAL, INTEGER) RETURNS VOID AS '$$"libdir"/$$obj', '$$func' LANGUAGE 'c' STRICT;"; \
 		echo "DROP CONVERSION pg_catalog.$$name;"; \
 		echo "CREATE DEFAULT CONVERSION pg_catalog.$$name FOR '$$se' TO '$$de' FROM $$func;"; \
 	done > $@