diff --git a/matcher/api.py b/matcher/api.py
index 5de289e..8b6aee5 100644
--- a/matcher/api.py
+++ b/matcher/api.py
@@ -418,7 +418,7 @@ def wikidata_items_count(bounds, isa_filter=None):
 
     return q.count()
 
-def wikidata_isa_counts(bounds):
+def wikidata_isa_counts(bounds, isa_filter=None):
     db_bbox = make_envelope(bounds)
 
     q = (
@@ -426,6 +426,9 @@ def wikidata_isa_counts(bounds):
         .filter(func.ST_Covers(db_bbox, model.ItemLocation.location))
     )
 
+    if isa_filter:
+        q = add_isa_filter(q, isa_filter)
+
     db_items = q.all()
 
     counts = get_isa_count(db_items)