diff --git a/client/agent.c b/client/agent.c
index 121a16ae..5844acdd 100644
--- a/client/agent.c
+++ b/client/agent.c
@@ -50,6 +50,19 @@ static struct pending_op {
 	struct l_queue *saved_input;
 } pending_op;
 
+static struct l_dbus_message *agent_error(const char *text)
+{
+	display_error(text);
+
+	if (!command_is_interactive_mode()) {
+		command_set_exit_status(EXIT_FAILURE);
+
+		l_main_quit();
+	}
+
+	return NULL;
+}
+
 static struct l_dbus_message *release_method_call(struct l_dbus *dbus,
 						struct l_dbus_message *message,
 						void *user_data)
@@ -94,6 +107,11 @@ static struct l_dbus_message *request_passphrase_method_call(
 	if (reply)
 		return reply;
 
+	if (command_option_get(COMMAND_OPTION_DONTASK, NULL))
+		return agent_error("No passphrase is provided as "
+					"'--"COMMAND_OPTION_PASSPHRASE"' "
+						"command-line option.\n");
+
 	l_dbus_message_get_arguments(message, "o", &path);
 	if (!path)
 		return NULL;
@@ -130,6 +148,11 @@ static struct l_dbus_message *request_private_key_passphrase_method_call(
 	if (reply)
 		return reply;
 
+	if (command_option_get(COMMAND_OPTION_DONTASK, NULL))
+		return agent_error("No passphrase is provided as "
+					"'--"COMMAND_OPTION_PASSPHRASE"' "
+						"command-line option.\n");
+
 	l_dbus_message_get_arguments(message, "o", &path);
 	if (!path)
 		return NULL;
@@ -187,6 +210,12 @@ static struct l_dbus_message *request_username_and_password_method_call(
 	if (reply)
 		return reply;
 
+	if (command_option_get(COMMAND_OPTION_DONTASK, NULL))
+		return agent_error("No username or password is provided as "
+					"'--"COMMAND_OPTION_USERNAME"' or "
+					"'--"COMMAND_OPTION_PASSWORD"' "
+						"command-line option.\n");
+
 	l_dbus_message_get_arguments(message, "o", &path);
 	if (!path)
 		return NULL;
@@ -241,6 +270,11 @@ static struct l_dbus_message *request_user_password_method_call(
 	if (reply)
 		return reply;
 
+	if (command_option_get(COMMAND_OPTION_DONTASK, NULL))
+		return agent_error("No password is provided as "
+					"'--"COMMAND_OPTION_PASSWORD"' "
+					"command-line option.\n");
+
 	l_dbus_message_get_arguments(message, "os", &path, &username);
 	if (!path || !username)
 		return NULL;