diff --git a/tests/test_command.sh b/tests/test_command.sh
index eba4c8c..0995299 100755
--- a/tests/test_command.sh
+++ b/tests/test_command.sh
@@ -36,5 +36,7 @@ $LOCAL 2>/dev/null 1>/dev/null -m rc4-md5 -k testrc4 -s 127.0.0.1 -p 8388 -d sto
 assert "$SERVER 2>&1 -m rc4-md5 -p 8388 -s 0.0.0.0 -d start | grep ERROR |  awk -F\"ERROR\" '{print \$2}'" ": password or port_password not specified"
 $LOCAL 2>/dev/null 1>/dev/null -m rc4-md5 -k testrc4 -s 127.0.0.1 -p 8388 -d stop
 
+assert "$SERVER 2>&1 --forbidden-ip 127.0.0.1/4a -m rc4-md5 -k 12345 -p 8388 -s 0.0.0.0 -d start | grep ERROR |  awk -F\"ERROR\" '{print \$2}'" ": Not a valid CIDR notation: 127.0.0.1/4a"
+$LOCAL 2>/dev/null 1>/dev/null -m rc4-md5 -k testrc4 -s 127.0.0.1 -p 8388 -d stop
 
 assert_end command