diff --git a/tests/test_sparql.py b/tests/test_sparql.py
index ef7e163..4146c49 100644
--- a/tests/test_sparql.py
+++ b/tests/test_sparql.py
@@ -1,7 +1,7 @@
 import json
 import unittest
 
-from rdflib import RDF, ConjunctiveGraph, Graph, Namespace
+from rdflib import RDF, ConjunctiveGraph, Dataset, Graph, Namespace
 
 EX = Namespace("http://example.com/")
 
@@ -33,7 +33,6 @@ def test_select_query_graph(self):
         g = Graph("Oxigraph")
         g.add((EX.foo, RDF.type, EX.Entity))
         result = g.query("SELECT ?s WHERE { ?s ?p ?o }")
-        self.assertEqual(len(result), 1)
         self.assertEqual(
             json.loads(result.serialize(format="json").decode("utf-8")),
             {
@@ -46,7 +45,30 @@ def test_select_query_conjunctive(self):
         g = ConjunctiveGraph("Oxigraph")
         g.add((EX.foo, RDF.type, EX.Entity))
         result = g.query("SELECT ?s WHERE { ?s ?p ?o }")
-        self.assertEqual(len(result), 1)
+        self.assertEqual(
+            json.loads(result.serialize(format="json").decode("utf-8")),
+            {
+                "results": {"bindings": [{"s": {"type": "uri", "value": "http://example.com/foo"}}]},
+                "head": {"vars": ["s"]},
+            },
+        )
+
+    def test_select_query_dataset(self):
+        g = Dataset("Oxigraph")
+        g.add((EX.foo, RDF.type, EX.Entity))
+        result = g.query("SELECT ?s WHERE { ?s ?p ?o }")
+        self.assertEqual(
+            json.loads(result.serialize(format="json").decode("utf-8")),
+            {
+                "results": {"bindings": [{"s": {"type": "uri", "value": "http://example.com/foo"}}]},
+                "head": {"vars": ["s"]},
+            },
+        )
+
+    def test_select_query_dataset_default_union(self):
+        g = Dataset("Oxigraph", default_union=True)
+        g.add((EX.foo, RDF.type, EX.Entity, EX.graph))
+        result = g.query("SELECT ?s WHERE { ?s ?p ?o }")
         self.assertEqual(
             json.loads(result.serialize(format="json").decode("utf-8")),
             {
@@ -59,12 +81,41 @@ def test_construct_query(self):
         g = ConjunctiveGraph("Oxigraph")
         g.add((EX.foo, RDF.type, EX.Entity))
         result = g.query("CONSTRUCT WHERE { ?s ?p ?o }")
-        self.assertEqual(len(result), 1)
         self.assertEqual(
             result.serialize(format="ntriples").strip(),
             b"<http://example.com/foo> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://example.com/Entity> .",
         )
 
+    def test_insert_where_update_graph(self):
+        g = Graph("Oxigraph")
+        g.add((EX.foo, RDF.type, EX.Entity))
+        g.update("INSERT { ?s a <http://example.com/Entity2> } WHERE { ?s a <http://example.com/Entity> }")
+        self.assertIn((EX.foo, RDF.type, EX.Entity2), g)
+
+    def test_insert_where_update_conjunctive_graph(self):
+        g = ConjunctiveGraph("Oxigraph")
+        g.add((EX.foo, RDF.type, EX.Entity, EX.g))
+        g.update("INSERT { ?s a <http://example.com/Entity2> } WHERE { ?s a <http://example.com/Entity> }")
+        self.assertIn((EX.foo, RDF.type, EX.Entity2), g)
+
+    def test_insert_where_update_dataset_named_graph(self):
+        g = Dataset("Oxigraph")
+        g.add((EX.foo, RDF.type, EX.Entity, EX.g))
+        g.update("INSERT { ?s a <http://example.com/Entity2> } WHERE { GRAPH ?g { ?s a <http://example.com/Entity> } }")
+        self.assertIn((EX.foo, RDF.type, EX.Entity2, g), g)  # RDFlib issue #2019
+
+    def test_insert_where_update_dataset_default_graph(self):
+        g = Dataset("Oxigraph")
+        g.add((EX.foo, RDF.type, EX.Entity))
+        g.update("INSERT { ?s a <http://example.com/Entity2> } WHERE { ?s a <http://example.com/Entity> }")
+        self.assertIn((EX.foo, RDF.type, EX.Entity2, g.identifier), g)  # RDFlib issue #2019
+
+    def test_insert_where_update_dataset_default_union(self):
+        g = Dataset("Oxigraph", default_union=True)
+        g.add((EX.foo, RDF.type, EX.Entity, EX.g))
+        g.update("INSERT { ?s a <http://example.com/Entity2> } WHERE { ?s a <http://example.com/Entity> }")
+        self.assertIn((EX.foo, RDF.type, EX.Entity2, g.identifier), g)  # RDFlib issue #2019
+
 
 if __name__ == "__main__":
     unittest.main()