diff --git a/oda_api/ontology_helper.py b/oda_api/ontology_helper.py
index 8b9a22a2..14f7b0d6 100644
--- a/oda_api/ontology_helper.py
+++ b/oda_api/ontology_helper.py
@@ -246,14 +246,14 @@ def get_uri_hierarchy(self, uri, base_uri):
         uri_m = self._normalize_uri(uri)
         base_uri_m = self._normalize_uri(base_uri)
         query = """
-        select ?mid ( count(?mid2) as ?midcount ) where { 
+        SELECT ?mid ( count(?mid2) as ?midcount ) WHERE { 
         %s  (rdfs:subClassOf|a)* ?mid . 
         
         ?mid rdfs:subClassOf* ?mid2 .
         ?mid2 rdfs:subClassOf* %s .
         }
-        group by ?mid
-        order by desc(?midcount)
+        GROUP BY ?mid
+        ORDER BY DESC(?midcount)
         """ % ( uri_m, base_uri_m )
 
         qres = self.g.query(query)
@@ -381,14 +381,10 @@ def get_allowed_values(self, param_uri):
     
     def get_parprod_terms(self):
         query = """
-            SELECT ?s WHERE {
+            SELECT DISTINCT ?s WHERE {
                 ?s (rdfs:subClassOf|a)* ?mid0.
-                ?mid0 rdfs:subClassOf* oda:DataProduct. 
-
-                ?s (rdfs:subClassOf|a)* ?mid1.
-                ?mid1 rdfs:subClassOf* oda:WorkflowParameter .
+                ?mid0 rdfs:subClassOf* oda:ParameterProduct .
             }
-            GROUP BY ?s
             """
         qres = self.g.query(query)
         return [str(row[0]) for row in qres]
diff --git a/tests/test_ontology.py b/tests/test_ontology.py
index cb64a4a7..f4907155 100644
--- a/tests/test_ontology.py
+++ b/tests/test_ontology.py
@@ -387,3 +387,11 @@ def test_get_requested_resources(onto):
     assert data[0] == dict(resource="MyS3", required=True, env_vars=set(["My_S3_CREDENTIALS"]))
     data = list(onto.get_requested_resources(g))
     assert len(data) == 2
+
+def test_parprod_terms(onto):
+    parprod = onto.get_parprod_terms()
+    assert parprod[0] == 'http://odahub.io/ontology#ParameterProduct'
+    assert 'http://odahub.io/ontology#Float' in parprod
+    assert 'http://odahub.io/ontology#String' in parprod
+    assert 'http://odahub.io/ontology#StartTimeISOT' in parprod
+    
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