diff --git a/js/README.md b/js/README.md
index f21c1d12..94a2847d 100644
--- a/js/README.md
+++ b/js/README.md
@@ -188,6 +188,18 @@ if (store.query("ASK { ?s ?s ?s }")) {
 }
 ```
 
+It is also possible to provide some options in an object given as second argument:
+
+```js
+if (store.query("ASK { <s> ?p ?o }", {
+  base_iri: "http://example.com/", // base IRI to resolve relative IRIs in the query
+  use_default_graph_as_union: true, // the default graph in the query is the union of all the dataset graphs
+
+})) {
+  console.log("there is a triple with same subject, predicate and object");
+}
+```
+
 #### `Store.prototype.update(String query)`
 Executes a [SPARQL 1.1 Update](https://www.w3.org/TR/sparql11-update/).
 The [`LOAD` operation](https://www.w3.org/TR/sparql11-update/#load) is not supported yet.
@@ -197,6 +209,14 @@ Example of update:
 store.update("DELETE WHERE { <http://example.com/s> ?p ?o }")
 ```
 
+It is also possible to provide some options in an object given as second argument:
+
+```js
+store.update("DELETE WHERE { <s> ?p ?o }", {
+  base_iri: "http://example.com/" // base IRI to resolve relative IRIs in the update
+})
+```
+
 #### `Store.prototype.load(String data, String format, NamedNode|String? baseIRI, NamedNode|BlankNode|DefaultGraph? toNamedGraph)`
 
 Loads serialized RDF triples or quad into the store.
diff --git a/js/src/store.rs b/js/src/store.rs
index 0b4b51b8..b1df4dfb 100644
--- a/js/src/store.rs
+++ b/js/src/store.rs
@@ -1,10 +1,10 @@
 use crate::format_err;
 use crate::model::*;
 use crate::utils::to_err;
-use js_sys::{Array, Map};
+use js_sys::{Array, Map, Reflect};
 use oxigraph::io::{RdfFormat, RdfParser};
 use oxigraph::model::*;
-use oxigraph::sparql::QueryResults;
+use oxigraph::sparql::{Query, QueryResults, Update};
 use oxigraph::store::Store;
 use wasm_bindgen::prelude::*;
 
@@ -102,7 +102,21 @@ impl JsStore {
             .into_boxed_slice())
     }
 
-    pub fn query(&self, query: &str) -> Result<JsValue, JsValue> {
+    pub fn query(&self, query: &str, options: &JsValue) -> Result<JsValue, JsValue> {
+        // Parsing options
+        let mut base_iri = None;
+        let mut use_default_graph_as_union = false;
+        if !options.is_undefined() {
+            base_iri = Reflect::get(options, &JsValue::from_str("base_iri"))?.as_string();
+            use_default_graph_as_union =
+                Reflect::get(options, &JsValue::from_str("use_default_graph_as_union"))?
+                    .is_truthy();
+        }
+
+        let mut query = Query::parse(query, base_iri.as_deref()).map_err(to_err)?;
+        if use_default_graph_as_union {
+            query.dataset_mut().set_default_graph_as_union();
+        }
         let results = self.store.query(query).map_err(to_err)?;
         let output = match results {
             QueryResults::Solutions(solutions) => {
@@ -135,7 +149,14 @@ impl JsStore {
         Ok(output)
     }
 
-    pub fn update(&self, update: &str) -> Result<(), JsValue> {
+    pub fn update(&self, update: &str, options: &JsValue) -> Result<(), JsValue> {
+        // Parsing options
+        let mut base_iri = None;
+        if !options.is_undefined() {
+            base_iri = Reflect::get(options, &JsValue::from_str("base_iri"))?.as_string();
+        }
+
+        let update = Update::parse(update, base_iri.as_deref()).map_err(to_err)?;
         self.store.update(update).map_err(to_err)
     }
 
diff --git a/js/test/store.mjs b/js/test/store.mjs
index 0693ac47..7d9bc5dd 100644
--- a/js/test/store.mjs
+++ b/js/test/store.mjs
@@ -90,6 +90,22 @@ describe("Store", () => {
             const results = store.query("SELECT (RAND() AS ?y) WHERE {}");
             assert.strictEqual(1, results.length);
         });
+
+        it("SELECT with base IRI", () => {
+            const store = new Store();
+            const results = store.query("SELECT * WHERE { BIND(<t> AS ?t) }", {
+                base_iri: "http://example.com/",
+            });
+            assert.strictEqual(1, results.length);
+        });
+
+        it("SELECT with union graph", () => {
+            const store = new Store([dataModel.quad(ex, ex, ex, ex)]);
+            const results = store.query("SELECT * WHERE { ?s ?p ?o }", {
+                use_default_graph_as_union: true,
+            });
+            assert.strictEqual(1, results.length);
+        });
     });
 
     describe("#update()", () => {