diff --git a/Intel-Systems/common/isbc208.c b/Intel-Systems/common/isbc208.c
index ae2ab747..cbfc5a29 100644
--- a/Intel-Systems/common/isbc208.c
+++ b/Intel-Systems/common/isbc208.c
@@ -512,7 +512,7 @@ extern void clr_irq(int32 int_num);
 extern uint8 reg_dev(uint8 (*routine)(t_bool, uint8, uint8), uint16, uint16, uint8);
 extern uint8 unreg_dev(uint16);
 extern void multibus_put_mbyte(uint16 addr, uint8 val);
-extern int32 multibus_get_mbyte(uint16 addr);
+extern uint8 multibus_get_mbyte(uint16 addr);
  
 /* external globals */