diff --git a/CHANGELOG.md b/CHANGELOG.md
index 43ab3a100..3e4558bd7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,4 @@
+- core: prevent crash when merging dives without cylinders (as we might get when importing from divelogs.de)
 - core: work around bug in TecDiving dive computer reporting spurious 0 deg C water temperature in first sample
 - core: correctly parse DC_FIELD_SALINITY response; fixes incorrect water type with some dive computers, including the Mares Smart
 - Desktop: Allow more than one media file to be imported from web
diff --git a/core/dive.c b/core/dive.c
index 03eb82e70..1d20e1421 100644
--- a/core/dive.c
+++ b/core/dive.c
@@ -2623,8 +2623,10 @@ struct dive *merge_dives(const struct dive *a, const struct dive *b, int offset,
 	MERGE_NONZERO(res, a, b, visibility);
 	copy_pictures(a->pictures.nr ? &a->pictures : &b->pictures, &res->pictures);
 	taglist_merge(&res->tag_list, a->tag_list, b->tag_list);
-	cylinders_map_a = malloc(a->cylinders.nr * sizeof(*cylinders_map_a));
-	cylinders_map_b = malloc(b->cylinders.nr * sizeof(*cylinders_map_b));
+	/* if we get dives without any gas / cylinder information in an import, make sure
+	 * that there is at leatst one entry in the cylinder map for that dive */
+	cylinders_map_a = malloc(MAX(1, a->cylinders.nr) * sizeof(*cylinders_map_a));
+	cylinders_map_b = malloc(MAX(1, b->cylinders.nr) * sizeof(*cylinders_map_b));
 	merge_cylinders(res, a, b, cylinders_map_a, cylinders_map_b);
 	merge_equipment(res, a, b);
 	merge_temperatures(res, a, b);