diff --git a/tests/p_postfix/postfix_smtp.sh b/tests/p_postfix/postfix_smtp.sh
index 64a76f9..7489f6d 100755
--- a/tests/p_postfix/postfix_smtp.sh
+++ b/tests/p_postfix/postfix_smtp.sh
@@ -3,6 +3,6 @@
 
 t_Log "Running $0 - Postfix SMTP test."
 
-echo "helo test" | nc -w 3 localhost 25 | grep '250'
+echo "helo test" | nc -w 3 localhost 25 | grep -q '250'
 
 t_CheckExitStatus $?
diff --git a/tests/p_sendmail/sendmail_smtp.sh b/tests/p_sendmail/sendmail_smtp.sh
index 9383774..dba02b1 100755
--- a/tests/p_sendmail/sendmail_smtp.sh
+++ b/tests/p_sendmail/sendmail_smtp.sh
@@ -3,6 +3,6 @@
 
 t_Log "Running $0 - Sendmail SMTP test."
 
-echo "helo test" | nc -w 3 localhost 25 | grep '250'
+echo "helo test" | nc -w 3 localhost 25 | grep -q '250'
 
 t_CheckExitStatus $?