diff --git a/src/suunto_eonsteel_parser.c b/src/suunto_eonsteel_parser.c
index afa99d6..86a60c4 100644
--- a/src/suunto_eonsteel_parser.c
+++ b/src/suunto_eonsteel_parser.c
@@ -576,6 +576,7 @@ static void sample_gas_switch_event(struct sample_data *info, unsigned short idx
 
 	sample.event.type = SAMPLE_EVENT_GASCHANGE2;
 	sample.event.value = o2 | (he << 16);
+	sample.event.flags = idx;
 
 	if (info->callback) info->callback(DC_SAMPLE_EVENT, sample, info->userdata);
 }