diff --git a/src/main.vala b/src/main.vala
index 8c31254..661a3aa 100644
--- a/src/main.vala
+++ b/src/main.vala
@@ -25,9 +25,9 @@ string earpiece_mixer;
 string card_name;
 
 private const GLib.OptionEntry[] options = {
-    { "speaker", 's', OptionFlags.NONE, OptionArg.STRING, ref speaker_mixer, "mixer for speaker mode", "QUAT_MI2S_RX Voice Mixer VoiceMMode1" },
-    { "earpiece", 'e', OptionFlags.NONE, OptionArg.STRING, ref earpiece_mixer, "mixer for earpiece mode", "SLIMBUS_0_RX Voice Mixer VoiceMMode1" },
-    { "card", 'c', OptionFlags.NONE, OptionArg.STRING, ref card_name, "alsa card", "hw:0" },
+    { "speaker", 's', OptionFlags.IN_MAIN, OptionArg.STRING, ref speaker_mixer, "mixer for speaker mode", "QUAT_MI2S_RX Voice Mixer VoiceMMode1" },
+    { "earpiece", 'e', OptionFlags.IN_MAIN, OptionArg.STRING, ref earpiece_mixer, "mixer for earpiece mode", "SLIMBUS_0_RX Voice Mixer VoiceMMode1" },
+    { "card", 'c', OptionFlags.IN_MAIN, OptionArg.STRING, ref card_name, "alsa card", "hw:0" },
     { null }
 };
 
@@ -81,6 +81,9 @@ int main (string[] args) {
         printerr ("Run '%s --help' to see a full list of available command line options.\n", args[0]);
         return 1;
     }
+    if (speaker_mixer == null || earpiece_mixer == null || card_name == null) {
+        error ("Run --help to get options. You need to specify card, speaker and earpiece");
+    }
 
     Alsa.Card card;
     message ("Card open: %d", Alsa.Card.open (out card, card_name, Alsa.CardOpenType.NONBLOCK));