diff --git a/src/chipset/contaq_82c59x.c b/src/chipset/contaq_82c59x.c
index eb9ed9cdd..93c841b9b 100644
--- a/src/chipset/contaq_82c59x.c
+++ b/src/chipset/contaq_82c59x.c
@@ -83,7 +83,7 @@ contaq_82c59x_isa_speed_recalc(contaq_82c59x_t *dev)
 		case 0x02:
 			cpu_set_isa_speed(cpu_busspeed / 8);
 			break;
-		case 0x04:
+		case 0x03:
 			cpu_set_isa_speed(cpu_busspeed / 5);
 			break;
 	}