diff --git a/Makefile b/Makefile
index 696f4e6..5be73a9 100644
--- a/Makefile
+++ b/Makefile
@@ -3,6 +3,7 @@ all: ncbitaxon.owl ncbitaxon.obo ncbitaxon.json ncbi_diff_latest_current_obo.txt
 all: ncbitaxon.owl.gz ncbitaxon.obo.gz ncbitaxon.json.gz
 
 ROBOT=robot
+DATE=$(shell date '+%Y-%m-01')
 
 .PHONY: clean
 clean:
@@ -12,7 +13,7 @@ build:
 	mkdir -p $@
 
 build/taxdmp.zip: | build
-	curl -L -o $@ https://ftp.ncbi.nih.gov/pub/taxonomy/taxdmp.zip
+	curl -L -o $@ https://ftp.ncbi.nih.gov/pub/taxonomy/taxdump_archive/taxdmp_$(DATE).zip
 
 ncbitaxon.ttl: src/ncbitaxon.py build/taxdmp.zip
 	python3 $^ $@
diff --git a/src/ncbitaxon.py b/src/ncbitaxon.py
index d6a6200..ef44e6f 100755
--- a/src/ncbitaxon.py
+++ b/src/ncbitaxon.py
@@ -187,6 +187,7 @@ def convert(taxdmp_path, output_path, taxa=None):
     citations = defaultdict(list)
     with open(output_path, "w") as output:
         isodate = date.today().isoformat()
+        ncbi_date = date.today().replace(day=1)
         output.write(
             f"""@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
 @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@@ -205,6 +206,7 @@ def convert(taxdmp_path, output_path, taxa=None):
 ; terms:description "An ontology representation of the NCBI organismal taxonomy"
 ; terms:license <https://creativecommons.org/publicdomain/zero/1.0/>
 ; rdfs:comment "Built by https://github.com/obophenotype/ncbitaxon"^^xsd:string
+; rdfs:comment "NCBI organismal taxonomy version {ncbi_date}"^^xsd:string
 .
 
 obo:IAO_0000115 a owl:AnnotationProperty