diff --git a/tty3270-on-serial-line-of-s390.patch b/tty3270-on-serial-line-of-s390.patch
index 20877b1..8e5b4d2 100644
--- a/tty3270-on-serial-line-of-s390.patch
+++ b/tty3270-on-serial-line-of-s390.patch
@@ -32,7 +32,7 @@ is compatible with VT220.
 +		 * higher.  Whereas the second serial line on a S/390(x) is
 +		 * a real character terminal which is compatible with VT220.
 +		 */
-+		if (strcmp(op->tty, "ttyS0") == 0 || strncmp(op->tty, "3270/tty", 8))
++		if (strcmp(op->tty, "ttyS0") == 0 || strncmp(op->tty, "3270/tty", 8) == 0)
 +			op->term = DEFAULT_TTYS0;
 +		else if (strcmp(op->tty, "ttyS1") == 0)
 +			op->term = DEFAULT_TTYS1;