diff --git a/lib/oxrdf/src/triple.rs b/lib/oxrdf/src/triple.rs
index c0328f46..850b1375 100644
--- a/lib/oxrdf/src/triple.rs
+++ b/lib/oxrdf/src/triple.rs
@@ -853,10 +853,11 @@ impl<'a> From<TripleRef<'a>> for Triple {
 
 /// A possible owned graph name.
 /// It is the union of [IRIs](https://www.w3.org/TR/rdf11-concepts/#dfn-iri), [blank nodes](https://www.w3.org/TR/rdf11-concepts/#dfn-blank-node), and the [default graph name](https://www.w3.org/TR/rdf11-concepts/#dfn-default-graph).
-#[derive(Eq, PartialEq, Debug, Clone, Hash)]
+#[derive(Eq, PartialEq, Debug, Clone, Hash, Default)]
 pub enum GraphName {
     NamedNode(NamedNode),
     BlankNode(BlankNode),
+    #[default]
     DefaultGraph,
 }
 
@@ -940,10 +941,11 @@ impl From<NamedOrBlankNodeRef<'_>> for GraphName {
 
 /// A possible borrowed graph name.
 /// It is the union of [IRIs](https://www.w3.org/TR/rdf11-concepts/#dfn-iri), [blank nodes](https://www.w3.org/TR/rdf11-concepts/#dfn-blank-node), and the [default graph name](https://www.w3.org/TR/rdf11-concepts/#dfn-default-graph).
-#[derive(Eq, PartialEq, Debug, Clone, Copy, Hash)]
+#[derive(Eq, PartialEq, Debug, Clone, Copy, Hash, Default)]
 pub enum GraphNameRef<'a> {
     NamedNode(NamedNodeRef<'a>),
     BlankNode(BlankNodeRef<'a>),
+    #[default]
     DefaultGraph,
 }
 
diff --git a/lib/spargebra/src/term.rs b/lib/spargebra/src/term.rs
index 8c41fc1b..6a33294c 100644
--- a/lib/spargebra/src/term.rs
+++ b/lib/spargebra/src/term.rs
@@ -183,9 +183,10 @@ impl TryFrom<Triple> for GroundTriple {
 /// A possible graph name.
 ///
 /// It is the union of [IRIs](https://www.w3.org/TR/rdf11-concepts/#dfn-iri) and the [default graph name](https://www.w3.org/TR/rdf11-concepts/#dfn-default-graph).
-#[derive(Eq, PartialEq, Debug, Clone, Hash)]
+#[derive(Eq, PartialEq, Debug, Clone, Hash, Default)]
 pub enum GraphName {
     NamedNode(NamedNode),
+    #[default]
     DefaultGraph,
 }