diff --git a/qt-ui/profile/diveeventitem.cpp b/qt-ui/profile/diveeventitem.cpp
index 700430007..0d81e7b45 100644
--- a/qt-ui/profile/diveeventitem.cpp
+++ b/qt-ui/profile/diveeventitem.cpp
@@ -135,7 +135,9 @@ bool DiveEventItem::shouldBeHidden()
 	 * Don't bother showing those
 	 */
 	struct sample *first_sample = &get_dive_dc(&displayed_dive, dc_number)->sample[0];
-	if (!strcmp(event->name, "gaschange") && first_sample && event->time.seconds == first_sample->time.seconds)
+	if (!strcmp(event->name, "gaschange") &&
+	    (event->time.seconds == 0 ||
+	     (first_sample && event->time.seconds == first_sample->time.seconds)))
 		return true;
 
 	for (int i = 0; i < evn_used; i++) {
diff --git a/statistics.c b/statistics.c
index 17176f714..1b2a1a6d3 100644
--- a/statistics.c
+++ b/statistics.c
@@ -306,7 +306,8 @@ bool is_cylinder_used(struct dive *dive, int idx)
 	for_each_dc(dive, dc) {
 		struct event *event = get_next_event(dc->events, "gaschange");
 		while (event) {
-			if (dc->sample && event->time.seconds == dc->sample[0].time.seconds)
+			if (dc->sample && (event->time.seconds == 0 ||
+					   (dc->samples && dc->sample[0].time.seconds == event->time.seconds)))
 				firstGasExplicit = true;
 			if (get_cylinder_index(dive, event) == idx)
 				return true;