diff --git a/src/gmnlm.c b/src/gmnlm.c

index a058caa10e6655aa6f516555717cd2c6df56759c..ff17c1a661ec9b95847b391e720964c4bab24e9d 100644

--- a/src/gmnlm.c

+++ b/src/gmnlm.c

@@ -1152,6 +1152,11 @@ }

if (n < 0) {

n = 0;

}

+ for (int i = 0; i < n; i++) {

+ if (iscntrl(buf[i]) && (buf[i] < '\t' || buf[i] > '\v')) {

+ buf[i] = '.';

+ }

+ }

ssize_t w = 0;

while (w < (ssize_t)n) {

ssize_t x = fwrite(&buf[w], 1, n - w, browser->tty);