diff --git a/code/datums/dna.dm b/code/datums/dna.dm
index 17cdb20e3c4..e5d4657c176 100644
--- a/code/datums/dna.dm
+++ b/code/datums/dna.dm
@@ -469,7 +469,9 @@ GLOBAL_LIST_INIT(total_uf_len_by_block, populate_total_uf_len_by_block())
 		generate_dna_blocks()
 	if(randomize_features)
 		for(var/species_type in GLOB.species_prototypes)
-			features |= GLOB.species_prototypes[species_type].randomize_features()
+			var/list/new_features = GLOB.species_prototypes[species_type].randomize_features()
+			for(var/feature in new_features)
+				features[feature] = new_features[feature]
 
 		features["mcolor"] = "#[random_color()]"