diff --git a/I1620/i1620_cpu.c b/I1620/i1620_cpu.c
index 3e08a47b..dc0e80d1 100644
--- a/I1620/i1620_cpu.c
+++ b/I1620/i1620_cpu.c
@@ -2428,7 +2428,7 @@ return SCPE_OK;
 t_stat cpu_show_hist (FILE *st, UNIT *uptr, int32 val, CONST void *desc)
 {
 int32 i, k, di, lnt;
-const char *cptr = (const char *) desc;
+CONST char *cptr = (CONST char *) desc;
 t_value sim_eval[INST_LEN];
 t_stat r;
 InstHistory *h;