diff --git a/unix/uxucs.c b/unix/uxucs.c
index fbd4e967..580f94b9 100644
--- a/unix/uxucs.c
+++ b/unix/uxucs.c
@@ -109,6 +109,6 @@ void init_ucs(void)
 
     for (i = 0; i < 256; i++) {
 	unitab_line[i] = unitab_scoacs[i] = i;
-	unitab_xterm[i] = i & 0x1F;
+	unitab_xterm[i] = (i+1) & 0x1F;
     }
 }
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