diff --git a/IBM360/ibm360_defs.h b/IBM360/ibm360_defs.h
index 5fce9ee..77373ce 100644
--- a/IBM360/ibm360_defs.h
+++ b/IBM360/ibm360_defs.h
@@ -354,8 +354,8 @@ t_stat show_dev_addr(FILE * st, UNIT * uptr, int32 v, CONST void *desc);
 extern uint16 loading;
 extern int    irq_pend;
 
-extern const char ascii_to_ebcdic[128];
-extern const char ebcdic_to_ascii[256];
+extern const uint8 ascii_to_ebcdic[128];
+extern const uint8 ebcdic_to_ascii[256];
 
 /* Debuging controls */
 #define DEBUG_CMD       0x0000001       /* Show device commands */
diff --git a/IBM360/ibm360_sys.c b/IBM360/ibm360_sys.c
index bfa5224..9d45606 100644
--- a/IBM360/ibm360_sys.c
+++ b/IBM360/ibm360_sys.c
@@ -120,7 +120,7 @@ const char *sim_stop_messages[SCPE_BASE] = {
     "Breakpoint"
      };
 
-const char ascii_to_ebcdic[128] = {
+const uint8 ascii_to_ebcdic[128] = {
    /* Control                              */
     0x01,0x02,0x03,0xFF,0x00,0x00,0x00,0x00,    /*0-37*/
    /*Control*/
@@ -155,7 +155,7 @@ const char ascii_to_ebcdic[128] = {
     0xa7, 0xa8, 0xa9, 0xc0, 0x47, 0xd0, 0xa1, 0x6d,
 };
 
-const char ebcdic_to_ascii[256] = {
+const uint8 ebcdic_to_ascii[256] = {
 /*      0     1     2     3    4     5      6   7 */
     0x00, 0x01, 0x02, 0x03, 0xFF, 0x09, 0x00, 0x7f,      /* 0x */
     0xff, 0xff, 0xff, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,