--- source/textBuf.c
+++ source/textBuf.c
@@ -1049,7 +1049,7 @@
     	return strlen(outStr);
     }
 #else
-    if (((unsigned char)c) <= 31) {
+    if (((unsigned char)c) <= 15) {
     	sprintf(outStr, "<%s>", ControlCodeTable[(unsigned char)c]);
     	return strlen(outStr);
     } else if (c == 127) {