diff --git a/src/system/boot/platform/bios_ia32/acpi.cpp b/src/system/boot/platform/bios_ia32/acpi.cpp
index f8d8754ba7..a4f2544ce3 100644
--- a/src/system/boot/platform/bios_ia32/acpi.cpp
+++ b/src/system/boot/platform/bios_ia32/acpi.cpp
@@ -56,7 +56,7 @@ acpi_check_rsdt(acpi_rsdp *rsdp)
 
 
 acpi_descriptor_header *
-acpi_find_table(char *signature)
+acpi_find_table(const char *signature)
 {
 	if (sAcpiRsdt == NULL)
 		return NULL;
diff --git a/src/system/boot/platform/bios_ia32/acpi.h b/src/system/boot/platform/bios_ia32/acpi.h
index 26847d823b..5577a220a4 100644
--- a/src/system/boot/platform/bios_ia32/acpi.h
+++ b/src/system/boot/platform/bios_ia32/acpi.h
@@ -18,7 +18,7 @@ struct scan_spots_struct {
 	uint32 length;
 };
 
-acpi_descriptor_header *acpi_find_table(char *signature);
+acpi_descriptor_header *acpi_find_table(const char *signature);
 void acpi_init(void);
 
 #ifdef __cplusplus