diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 2363ed173198..bdef2ce38c8b 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -199,7 +199,7 @@ char *__init __acpi_map_table(unsigned long phys_addr, unsigned long size)
 	return __va(phys_addr);
 }
 
-char *__init __acpi_unmap_table(unsigned long virt_addr, unsigned long size)
+void __init __acpi_unmap_table(char *map, unsigned long size)
 {
 }
 
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index d59f0fa4d772..78199151c00b 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -79,7 +79,7 @@ typedef int (*acpi_table_handler) (struct acpi_table_header *table);
 typedef int (*acpi_table_entry_handler) (struct acpi_subtable_header *header, const unsigned long end);
 
 char * __acpi_map_table (unsigned long phys_addr, unsigned long size);
-void __init __acpi_unmap_table(char *map, unsigned long size);
+void __acpi_unmap_table(char *map, unsigned long size);
 int early_acpi_boot_init(void);
 int acpi_boot_init (void);
 int acpi_boot_table_init (void);