diff --git a/stdpopsim/catalog/DroSec/genome_data.py b/stdpopsim/catalog/DroSec/genome_data.py
index 0f818b188..8f3d8cf56 100644
--- a/stdpopsim/catalog/DroSec/genome_data.py
+++ b/stdpopsim/catalog/DroSec/genome_data.py
@@ -1,6 +1,13 @@
-# File autogenerated from Ensembl REST API. Do not edit.
+# File created manually from https://www.ncbi.nlm.nih.gov/assembly/GCF_004382195.1
 data = {
-    "assembly_accession": "GCA_000005215.1",
-    "assembly_name": "dsec_caf1",
-    "chromosomes": {},
+    "assembly_accession": "GCA_004382195.1",
+    "assembly_name": "ASM438219v1",
+    "chromosomes": {
+        "2L": {"length": 24956976, "synonyms": []},
+        "2R": {"length": 21536224, "synonyms": []},
+        "3L": {"length": 28131630, "synonyms": []},
+        "3R": {"length": 30464902, "synonyms": []},
+        "X": {"length": 22909512, "synonyms": []},
+        "4": {"length": 1277805, "synonyms": []},
+    },
 }
diff --git a/stdpopsim/catalog/HelMel/genome_data.py b/stdpopsim/catalog/HelMel/genome_data.py
index 442658d34..4da71fa20 100644
--- a/stdpopsim/catalog/HelMel/genome_data.py
+++ b/stdpopsim/catalog/HelMel/genome_data.py
@@ -1,6 +1,37 @@
 # File autogenerated from Ensembl REST API. Do not edit.
+#
+# Manually edited. See
+# https://github.com/popsim-consortium/stdpopsim/issues/835#issuecomment-815854055
+#
+# Data source:
+# http://ensembl.lepbase.org/Heliconius_melpomene_melpomene_hmel25/Info/Index
+#
+# Chromosomes lengths from Davey et al. 2017
+#
 data = {
-    "assembly_accession": "GCA_000313835.1",
-    "assembly_name": "Hmel1",
-    "chromosomes": {},
+    "assembly_accession": None,  # No accession number available
+    "assembly_name": "Hmel2.5",
+    "chromosomes": {
+        "1": {"length": 17206585, "synonyms": []},
+        "2": {"length": 9045316, "synonyms": []},
+        "3": {"length": 10541528, "synonyms": []},
+        "4": {"length": 9662098, "synonyms": []},
+        "5": {"length": 9908586, "synonyms": []},
+        "6": {"length": 14054175, "synonyms": []},
+        "7": {"length": 14308859, "synonyms": []},
+        "8": {"length": 9320449, "synonyms": []},
+        "9": {"length": 8708747, "synonyms": []},
+        "10": {"length": 17965481, "synonyms": []},
+        "11": {"length": 11759272, "synonyms": []},
+        "12": {"length": 16327298, "synonyms": []},
+        "13": {"length": 18127314, "synonyms": []},
+        "14": {"length": 9174305, "synonyms": []},
+        "15": {"length": 10235750, "synonyms": []},
+        "16": {"length": 10083215, "synonyms": []},
+        "17": {"length": 14773299, "synonyms": []},
+        "18": {"length": 16803890, "synonyms": []},
+        "19": {"length": 16399344, "synonyms": []},
+        "20": {"length": 14871695, "synonyms": []},
+        "21": {"length": 13359691, "synonyms": []},
+    },
 }