diff --git a/lib/src/model/mod.rs b/lib/src/model/mod.rs
index 044c7ec1..940ab2d3 100644
--- a/lib/src/model/mod.rs
+++ b/lib/src/model/mod.rs
@@ -22,7 +22,8 @@ pub use self::literal::{Literal, LiteralRef};
 pub use self::named_node::{NamedNode, NamedNodeRef};
 pub use self::parser::TermParseError;
 pub use self::triple::{
-    GraphName, GraphNameRef, Quad, QuadRef, Subject, SubjectRef, Term, TermRef, Triple, TripleRef,
+    GraphName, GraphNameRef, NamedOrBlankNode, NamedOrBlankNodeRef, Quad, QuadRef, Subject,
+    SubjectRef, Term, TermRef, Triple, TripleRef,
 };
 pub use oxilangtag::LanguageTagParseError;
 pub use oxiri::IriParseError;
diff --git a/lib/src/model/triple.rs b/lib/src/model/triple.rs
index 786c436c..31cb8bc7 100644
--- a/lib/src/model/triple.rs
+++ b/lib/src/model/triple.rs
@@ -6,6 +6,163 @@ use rio_api::model as rio;
 use std::fmt;
 use std::sync::Arc;
 
+/// The owned union of [IRIs](https://www.w3.org/TR/rdf11-concepts/#dfn-iri) and [blank nodes](https://www.w3.org/TR/rdf11-concepts/#dfn-blank-node).
+#[derive(Eq, PartialEq, Debug, Clone, Hash)]
+pub enum NamedOrBlankNode {
+    NamedNode(NamedNode),
+    BlankNode(BlankNode),
+}
+
+impl NamedOrBlankNode {
+    #[inline]
+    pub fn is_named_node(&self) -> bool {
+        self.as_ref().is_named_node()
+    }
+
+    #[inline]
+    pub fn is_blank_node(&self) -> bool {
+        self.as_ref().is_blank_node()
+    }
+
+    #[inline]
+    pub fn as_ref(&self) -> NamedOrBlankNodeRef<'_> {
+        match self {
+            Self::NamedNode(node) => NamedOrBlankNodeRef::NamedNode(node.as_ref()),
+            Self::BlankNode(node) => NamedOrBlankNodeRef::BlankNode(node.as_ref()),
+        }
+    }
+}
+
+impl fmt::Display for NamedOrBlankNode {
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.as_ref().fmt(f)
+    }
+}
+
+impl From<NamedNode> for NamedOrBlankNode {
+    #[inline]
+    fn from(node: NamedNode) -> Self {
+        Self::NamedNode(node)
+    }
+}
+
+impl From<NamedNodeRef<'_>> for NamedOrBlankNode {
+    #[inline]
+    fn from(node: NamedNodeRef<'_>) -> Self {
+        node.into_owned().into()
+    }
+}
+
+impl From<BlankNode> for NamedOrBlankNode {
+    #[inline]
+    fn from(node: BlankNode) -> Self {
+        Self::BlankNode(node)
+    }
+}
+
+impl From<BlankNodeRef<'_>> for NamedOrBlankNode {
+    #[inline]
+    fn from(node: BlankNodeRef<'_>) -> Self {
+        node.into_owned().into()
+    }
+}
+
+/// The borrowed union of [IRIs](https://www.w3.org/TR/rdf11-concepts/#dfn-iri) and [blank nodes](https://www.w3.org/TR/rdf11-concepts/#dfn-blank-node).
+#[derive(Eq, PartialEq, Debug, Clone, Copy, Hash)]
+pub enum NamedOrBlankNodeRef<'a> {
+    NamedNode(NamedNodeRef<'a>),
+    BlankNode(BlankNodeRef<'a>),
+}
+
+impl<'a> NamedOrBlankNodeRef<'a> {
+    #[inline]
+    pub fn is_named_node(&self) -> bool {
+        match self {
+            Self::NamedNode(_) => true,
+            Self::BlankNode(_) => false,
+        }
+    }
+
+    #[inline]
+    pub fn is_blank_node(&self) -> bool {
+        match self {
+            Self::NamedNode(_) => false,
+            Self::BlankNode(_) => true,
+        }
+    }
+
+    #[inline]
+    pub fn into_owned(self) -> NamedOrBlankNode {
+        match self {
+            Self::NamedNode(node) => NamedOrBlankNode::NamedNode(node.into_owned()),
+            Self::BlankNode(node) => NamedOrBlankNode::BlankNode(node.into_owned()),
+        }
+    }
+}
+
+impl fmt::Display for NamedOrBlankNodeRef<'_> {
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::NamedNode(node) => node.fmt(f),
+            Self::BlankNode(node) => node.fmt(f),
+        }
+    }
+}
+
+impl<'a> From<NamedNodeRef<'a>> for NamedOrBlankNodeRef<'a> {
+    #[inline]
+    fn from(node: NamedNodeRef<'a>) -> Self {
+        Self::NamedNode(node)
+    }
+}
+
+impl<'a> From<&'a NamedNode> for NamedOrBlankNodeRef<'a> {
+    #[inline]
+    fn from(node: &'a NamedNode) -> Self {
+        node.as_ref().into()
+    }
+}
+
+impl<'a> From<BlankNodeRef<'a>> for NamedOrBlankNodeRef<'a> {
+    #[inline]
+    fn from(node: BlankNodeRef<'a>) -> Self {
+        Self::BlankNode(node)
+    }
+}
+
+impl<'a> From<&'a BlankNode> for NamedOrBlankNodeRef<'a> {
+    #[inline]
+    fn from(node: &'a BlankNode) -> Self {
+        node.as_ref().into()
+    }
+}
+
+impl<'a> From<&'a NamedOrBlankNode> for NamedOrBlankNodeRef<'a> {
+    #[inline]
+    fn from(node: &'a NamedOrBlankNode) -> Self {
+        node.as_ref()
+    }
+}
+
+impl<'a> From<NamedOrBlankNodeRef<'a>> for NamedOrBlankNode {
+    #[inline]
+    fn from(node: NamedOrBlankNodeRef<'a>) -> Self {
+        node.into_owned()
+    }
+}
+
+impl<'a> From<NamedOrBlankNodeRef<'a>> for rio::NamedOrBlankNode<'a> {
+    #[inline]
+    fn from(node: NamedOrBlankNodeRef<'a>) -> Self {
+        match node {
+            NamedOrBlankNodeRef::NamedNode(node) => rio::NamedNode::from(node).into(),
+            NamedOrBlankNodeRef::BlankNode(node) => rio::BlankNode::from(node).into(),
+        }
+    }
+}
+
 /// The owned 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 [triples](https://www.w3.org/TR/rdf11-concepts/#dfn-rdf-triple).
 #[derive(Eq, PartialEq, Debug, Clone, Hash)]
 pub enum Subject {
@@ -89,6 +246,23 @@ impl From<TripleRef<'_>> for Subject {
     }
 }
 
+impl From<NamedOrBlankNode> for Subject {
+    #[inline]
+    fn from(node: NamedOrBlankNode) -> Self {
+        match node {
+            NamedOrBlankNode::NamedNode(node) => node.into(),
+            NamedOrBlankNode::BlankNode(node) => node.into(),
+        }
+    }
+}
+
+impl From<NamedOrBlankNodeRef<'_>> for Subject {
+    #[inline]
+    fn from(node: NamedOrBlankNodeRef<'_>) -> Self {
+        node.into_owned().into()
+    }
+}
+
 /// The borrowed 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 [triples](https://www.w3.org/TR/rdf11-concepts/#dfn-rdf-triple).
 #[derive(Eq, PartialEq, Debug, Clone, Copy, Hash)]
 pub enum SubjectRef<'a> {
@@ -183,6 +357,23 @@ impl<'a> From<SubjectRef<'a>> for Subject {
     }
 }
 
+impl<'a> From<NamedOrBlankNodeRef<'a>> for SubjectRef<'a> {
+    #[inline]
+    fn from(node: NamedOrBlankNodeRef<'a>) -> Self {
+        match node {
+            NamedOrBlankNodeRef::NamedNode(node) => node.into(),
+            NamedOrBlankNodeRef::BlankNode(node) => node.into(),
+        }
+    }
+}
+
+impl<'a> From<&'a NamedOrBlankNode> for SubjectRef<'a> {
+    #[inline]
+    fn from(node: &'a NamedOrBlankNode) -> Self {
+        node.as_ref().into()
+    }
+}
+
 #[allow(clippy::unimplemented, clippy::fallible_impl_from)]
 impl<'a> From<SubjectRef<'a>> for rio::NamedOrBlankNode<'a> {
     #[inline]
@@ -299,6 +490,23 @@ impl From<TripleRef<'_>> for Term {
     }
 }
 
+impl From<NamedOrBlankNode> for Term {
+    #[inline]
+    fn from(node: NamedOrBlankNode) -> Self {
+        match node {
+            NamedOrBlankNode::NamedNode(node) => node.into(),
+            NamedOrBlankNode::BlankNode(node) => node.into(),
+        }
+    }
+}
+
+impl From<NamedOrBlankNodeRef<'_>> for Term {
+    #[inline]
+    fn from(node: NamedOrBlankNodeRef<'_>) -> Self {
+        node.into_owned().into()
+    }
+}
+
 impl From<Subject> for Term {
     #[inline]
     fn from(node: Subject) -> Self {
@@ -422,6 +630,23 @@ impl<'a> From<&'a Triple> for TermRef<'a> {
     }
 }
 
+impl<'a> From<NamedOrBlankNodeRef<'a>> for TermRef<'a> {
+    #[inline]
+    fn from(node: NamedOrBlankNodeRef<'a>) -> Self {
+        match node {
+            NamedOrBlankNodeRef::NamedNode(node) => node.into(),
+            NamedOrBlankNodeRef::BlankNode(node) => node.into(),
+        }
+    }
+}
+
+impl<'a> From<&'a NamedOrBlankNode> for TermRef<'a> {
+    #[inline]
+    fn from(node: &'a NamedOrBlankNode) -> Self {
+        node.as_ref().into()
+    }
+}
+
 impl<'a> From<SubjectRef<'a>> for TermRef<'a> {
     #[inline]
     fn from(node: SubjectRef<'a>) -> Self {
diff --git a/lib/src/sparql/algebra.rs b/lib/src/sparql/algebra.rs
index 38a116d1..44f17ae2 100644
--- a/lib/src/sparql/algebra.rs
+++ b/lib/src/sparql/algebra.rs
@@ -171,7 +171,7 @@ impl<'a> TryFrom<&'a String> for Update {
 #[derive(Eq, PartialEq, Debug, Clone, Hash)]
 pub struct QueryDataset {
     default: Option<Vec<GraphName>>,
-    named: Option<Vec<Subject>>,
+    named: Option<Vec<NamedOrBlankNode>>,
 }
 
 impl QueryDataset {
@@ -255,7 +255,7 @@ impl QueryDataset {
     }
 
     /// Returns the list of the available named graphs for the query or `None` if all graphs are available
-    pub fn available_named_graphs(&self) -> Option<&[Subject]> {
+    pub fn available_named_graphs(&self) -> Option<&[NamedOrBlankNode]> {
         self.named.as_deref()
     }
 
@@ -272,7 +272,7 @@ impl QueryDataset {
     ///
     /// # Result::Ok::<_, Box<dyn std::error::Error>>(())
     /// ```
-    pub fn set_available_named_graphs(&mut self, named_graphs: Vec<Subject>) {
+    pub fn set_available_named_graphs(&mut self, named_graphs: Vec<NamedOrBlankNode>) {
         self.named = Some(named_graphs);
     }
 }
diff --git a/lib/src/storage/numeric_encoder.rs b/lib/src/storage/numeric_encoder.rs
index 065d6c83..695bde75 100644
--- a/lib/src/storage/numeric_encoder.rs
+++ b/lib/src/storage/numeric_encoder.rs
@@ -601,6 +601,15 @@ impl From<LiteralRef<'_>> for EncodedTerm {
     }
 }
 
+impl From<NamedOrBlankNodeRef<'_>> for EncodedTerm {
+    fn from(term: NamedOrBlankNodeRef<'_>) -> Self {
+        match term {
+            NamedOrBlankNodeRef::NamedNode(named_node) => named_node.into(),
+            NamedOrBlankNodeRef::BlankNode(blank_node) => blank_node.into(),
+        }
+    }
+}
+
 impl From<SubjectRef<'_>> for EncodedTerm {
     fn from(term: SubjectRef<'_>) -> Self {
         match term {
@@ -737,6 +746,16 @@ pub(crate) trait WriteEncoder: StrContainer {
         self.encode_rio_literal(literal.into())
     }
 
+    fn encode_named_or_blank_node(
+        &self,
+        term: NamedOrBlankNodeRef<'_>,
+    ) -> Result<EncodedTerm, Self::Error> {
+        match term {
+            NamedOrBlankNodeRef::NamedNode(named_node) => self.encode_named_node(named_node),
+            NamedOrBlankNodeRef::BlankNode(blank_node) => self.encode_blank_node(blank_node),
+        }
+    }
+
     fn encode_subject(&self, term: SubjectRef<'_>) -> Result<EncodedTerm, Self::Error> {
         match term {
             SubjectRef::NamedNode(named_node) => self.encode_named_node(named_node),
@@ -1065,10 +1084,24 @@ pub(crate) trait Decoder: StrLookup {
             Term::NamedNode(named_node) => Ok(named_node.into()),
             Term::BlankNode(blank_node) => Ok(blank_node.into()),
             Term::Literal(_) => Err(DecoderError::Decoder {
-                msg: "A literal has been found instead of a named node".to_owned(),
+                msg: "A literal has been found instead of a subject node".to_owned(),
+            }),
+            Term::Triple(triple) => Ok(Subject::Triple(triple)),
+        }
+    }
+
+    fn decode_named_or_blank_node(
+        &self,
+        encoded: &EncodedTerm,
+    ) -> Result<NamedOrBlankNode, DecoderError<Self::Error>> {
+        match self.decode_term(encoded)? {
+            Term::NamedNode(named_node) => Ok(named_node.into()),
+            Term::BlankNode(blank_node) => Ok(blank_node.into()),
+            Term::Literal(_) => Err(DecoderError::Decoder {
+                msg: "A literal has been found instead of a named or blank node".to_owned(),
             }),
             Term::Triple(_) => Err(DecoderError::Decoder {
-                msg: "A triple has been found instead of a named node".to_owned(),
+                msg: "A triple has been found instead of a named or blank node".to_owned(),
             }),
         }
     }
diff --git a/lib/src/store.rs b/lib/src/store.rs
index 6afa0996..7f785160 100644
--- a/lib/src/store.rs
+++ b/lib/src/store.rs
@@ -439,7 +439,7 @@ impl Store {
     /// let store = Store::new()?;
     /// store.insert(QuadRef::new(&ex, &ex, &ex, &ex))?;
     /// store.insert(QuadRef::new(&ex, &ex, &ex, GraphNameRef::DefaultGraph))?;
-    /// assert_eq!(vec![Subject::from(ex)], store.named_graphs().collect::<Result<Vec<_>,_>>()?);
+    /// assert_eq!(vec![NamedOrBlankNode::from(ex)], store.named_graphs().collect::<Result<Vec<_>,_>>()?);
     /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
     /// ```
     pub fn named_graphs(&self) -> GraphNameIter {
@@ -464,7 +464,7 @@ impl Store {
     /// ```
     pub fn contains_named_graph<'a>(
         &self,
-        graph_name: impl Into<SubjectRef<'a>>,
+        graph_name: impl Into<NamedOrBlankNodeRef<'a>>,
     ) -> Result<bool, io::Error> {
         let graph_name = EncodedTerm::from(graph_name.into());
         self.storage.contains_named_graph(&graph_name)
@@ -487,9 +487,9 @@ impl Store {
     /// ```
     pub fn insert_named_graph<'a>(
         &self,
-        graph_name: impl Into<SubjectRef<'a>>,
+        graph_name: impl Into<NamedOrBlankNodeRef<'a>>,
     ) -> Result<bool, io::Error> {
-        let graph_name = self.storage.encode_subject(graph_name.into())?;
+        let graph_name = self.storage.encode_named_or_blank_node(graph_name.into())?;
         self.storage.insert_named_graph(&graph_name)
     }
 
@@ -541,7 +541,7 @@ impl Store {
     /// ```
     pub fn remove_named_graph<'a>(
         &self,
-        graph_name: impl Into<SubjectRef<'a>>,
+        graph_name: impl Into<NamedOrBlankNodeRef<'a>>,
     ) -> Result<bool, io::Error> {
         let graph_name = EncodedTerm::from(graph_name.into());
         self.storage.remove_named_graph(&graph_name)
@@ -706,9 +706,9 @@ impl Transaction<'_> {
     /// Returns `true` if the graph was not already in the store.
     pub fn insert_named_graph<'a>(
         &self,
-        graph_name: impl Into<SubjectRef<'a>>,
+        graph_name: impl Into<NamedOrBlankNodeRef<'a>>,
     ) -> Result<bool, UnabortableTransactionError> {
-        let graph_name = self.storage.encode_subject(graph_name.into())?;
+        let graph_name = self.storage.encode_named_or_blank_node(graph_name.into())?;
         self.storage.insert_named_graph(&graph_name)
     }
 }
@@ -737,13 +737,13 @@ pub struct GraphNameIter {
 }
 
 impl Iterator for GraphNameIter {
-    type Item = Result<Subject, io::Error>;
+    type Item = Result<NamedOrBlankNode, io::Error>;
 
-    fn next(&mut self) -> Option<Result<Subject, io::Error>> {
+    fn next(&mut self) -> Option<Result<NamedOrBlankNode, io::Error>> {
         Some(
-            self.iter
-                .next()?
-                .and_then(|graph_name| Ok(self.store.storage.decode_subject(&graph_name)?)),
+            self.iter.next()?.and_then(|graph_name| {
+                Ok(self.store.storage.decode_named_or_blank_node(&graph_name)?)
+            }),
         )
     }
 
diff --git a/lib/tests/store.rs b/lib/tests/store.rs
index d1dbf814..c4a2b146 100644
--- a/lib/tests/store.rs
+++ b/lib/tests/store.rs
@@ -181,7 +181,7 @@ fn test_backward_compatibility() -> io::Result<()> {
         }
         assert!(store.contains_named_graph(graph_name)?);
         assert_eq!(
-            vec![Subject::from(graph_name)],
+            vec![NamedOrBlankNode::from(graph_name)],
             store.named_graphs().collect::<io::Result<Vec<_>>>()?
         );
     };
diff --git a/python/src/model.rs b/python/src/model.rs
index 02bde29b..12e61db0 100644
--- a/python/src/model.rs
+++ b/python/src/model.rs
@@ -39,6 +39,12 @@ impl From<PyNamedNode> for NamedNode {
     }
 }
 
+impl From<PyNamedNode> for NamedOrBlankNode {
+    fn from(node: PyNamedNode) -> Self {
+        node.inner.into()
+    }
+}
+
 impl From<PyNamedNode> for Subject {
     fn from(node: PyNamedNode) -> Self {
         node.inner.into()
@@ -138,6 +144,12 @@ impl From<PyBlankNode> for BlankNode {
     }
 }
 
+impl From<PyBlankNode> for NamedOrBlankNode {
+    fn from(node: PyBlankNode) -> Self {
+        node.inner.into()
+    }
+}
+
 impl From<PyBlankNode> for Subject {
     fn from(node: PyBlankNode) -> Self {
         node.inner.into()
@@ -404,6 +416,39 @@ impl PyObjectProtocol for PyDefaultGraph {
     }
 }
 
+#[derive(FromPyObject)]
+pub enum PyNamedOrBlankNode {
+    NamedNode(PyNamedNode),
+    BlankNode(PyBlankNode),
+}
+
+impl From<PyNamedOrBlankNode> for NamedOrBlankNode {
+    fn from(node: PyNamedOrBlankNode) -> Self {
+        match node {
+            PyNamedOrBlankNode::NamedNode(node) => node.into(),
+            PyNamedOrBlankNode::BlankNode(node) => node.into(),
+        }
+    }
+}
+
+impl From<NamedOrBlankNode> for PyNamedOrBlankNode {
+    fn from(node: NamedOrBlankNode) -> Self {
+        match node {
+            NamedOrBlankNode::NamedNode(node) => Self::NamedNode(node.into()),
+            NamedOrBlankNode::BlankNode(node) => Self::BlankNode(node.into()),
+        }
+    }
+}
+
+impl IntoPy<PyObject> for PyNamedOrBlankNode {
+    fn into_py(self, py: Python<'_>) -> PyObject {
+        match self {
+            Self::NamedNode(node) => node.into_py(py),
+            Self::BlankNode(node) => node.into_py(py),
+        }
+    }
+}
+
 #[derive(FromPyObject)]
 pub enum PySubject {
     NamedNode(PyNamedNode),
@@ -424,9 +469,9 @@ impl From<PySubject> for Subject {
 impl From<Subject> for PySubject {
     fn from(node: Subject) -> Self {
         match node {
-            Subject::NamedNode(node) => PySubject::NamedNode(node.into()),
-            Subject::BlankNode(node) => PySubject::BlankNode(node.into()),
-            Subject::Triple(triple) => PySubject::Triple(triple.as_ref().clone().into()),
+            Subject::NamedNode(node) => Self::NamedNode(node.into()),
+            Subject::BlankNode(node) => Self::BlankNode(node.into()),
+            Subject::Triple(triple) => Self::Triple(triple.as_ref().clone().into()),
         }
     }
 }
@@ -434,9 +479,9 @@ impl From<Subject> for PySubject {
 impl IntoPy<PyObject> for PySubject {
     fn into_py(self, py: Python<'_>) -> PyObject {
         match self {
-            PySubject::NamedNode(node) => node.into_py(py),
-            PySubject::BlankNode(node) => node.into_py(py),
-            PySubject::Triple(triple) => triple.into_py(py),
+            Self::NamedNode(node) => node.into_py(py),
+            Self::BlankNode(node) => node.into_py(py),
+            Self::Triple(triple) => triple.into_py(py),
         }
     }
 }
@@ -463,10 +508,10 @@ impl From<PyTerm> for Term {
 impl From<Term> for PyTerm {
     fn from(term: Term) -> Self {
         match term {
-            Term::NamedNode(node) => PyTerm::NamedNode(node.into()),
-            Term::BlankNode(node) => PyTerm::BlankNode(node.into()),
-            Term::Literal(literal) => PyTerm::Literal(literal.into()),
-            Term::Triple(triple) => PyTerm::Triple(triple.as_ref().clone().into()),
+            Term::NamedNode(node) => Self::NamedNode(node.into()),
+            Term::BlankNode(node) => Self::BlankNode(node.into()),
+            Term::Literal(literal) => Self::Literal(literal.into()),
+            Term::Triple(triple) => Self::Triple(triple.as_ref().clone().into()),
         }
     }
 }
@@ -474,10 +519,10 @@ impl From<Term> for PyTerm {
 impl IntoPy<PyObject> for PyTerm {
     fn into_py(self, py: Python<'_>) -> PyObject {
         match self {
-            PyTerm::NamedNode(node) => node.into_py(py),
-            PyTerm::BlankNode(node) => node.into_py(py),
-            PyTerm::Literal(literal) => literal.into_py(py),
-            PyTerm::Triple(triple) => triple.into_py(py),
+            Self::NamedNode(node) => node.into_py(py),
+            Self::BlankNode(node) => node.into_py(py),
+            Self::Literal(literal) => literal.into_py(py),
+            Self::Triple(triple) => triple.into_py(py),
         }
     }
 }
@@ -645,9 +690,9 @@ impl From<PyGraphName> for GraphName {
 impl From<GraphName> for PyGraphName {
     fn from(graph_name: GraphName) -> Self {
         match graph_name {
-            GraphName::NamedNode(node) => PyGraphName::NamedNode(node.into()),
-            GraphName::BlankNode(node) => PyGraphName::BlankNode(node.into()),
-            GraphName::DefaultGraph => PyGraphName::DefaultGraph(PyDefaultGraph::new()),
+            GraphName::NamedNode(node) => Self::NamedNode(node.into()),
+            GraphName::BlankNode(node) => Self::BlankNode(node.into()),
+            GraphName::DefaultGraph => Self::DefaultGraph(PyDefaultGraph::new()),
         }
     }
 }
@@ -655,9 +700,9 @@ impl From<GraphName> for PyGraphName {
 impl IntoPy<PyObject> for PyGraphName {
     fn into_py(self, py: Python<'_>) -> PyObject {
         match self {
-            PyGraphName::NamedNode(node) => node.into_py(py),
-            PyGraphName::BlankNode(node) => node.into_py(py),
-            PyGraphName::DefaultGraph(node) => node.into_py(py),
+            Self::NamedNode(node) => node.into_py(py),
+            Self::BlankNode(node) => node.into_py(py),
+            Self::DefaultGraph(node) => node.into_py(py),
         }
     }
 }
@@ -943,9 +988,41 @@ impl<'a> TryFrom<&'a PyAny> for PyNamedNodeRef<'a> {
     }
 }
 
+pub enum PyNamedOrBlankNodeRef<'a> {
+    NamedNode(PyRef<'a, PyNamedNode>),
+    BlankNode(PyRef<'a, PyBlankNode>),
+}
+
+impl<'a> From<&'a PyNamedOrBlankNodeRef<'a>> for NamedOrBlankNodeRef<'a> {
+    fn from(value: &'a PyNamedOrBlankNodeRef<'a>) -> Self {
+        match value {
+            PyNamedOrBlankNodeRef::NamedNode(value) => value.inner.as_ref().into(),
+            PyNamedOrBlankNodeRef::BlankNode(value) => value.inner.as_ref().into(),
+        }
+    }
+}
+
+impl<'a> TryFrom<&'a PyAny> for PyNamedOrBlankNodeRef<'a> {
+    type Error = PyErr;
+
+    fn try_from(value: &'a PyAny) -> PyResult<Self> {
+        if let Ok(node) = value.downcast::<PyCell<PyNamedNode>>() {
+            Ok(Self::NamedNode(node.borrow()))
+        } else if let Ok(node) = value.downcast::<PyCell<PyBlankNode>>() {
+            Ok(Self::BlankNode(node.borrow()))
+        } else {
+            Err(PyTypeError::new_err(format!(
+                "{} is not an RDF named or blank node",
+                value.get_type().name()?,
+            )))
+        }
+    }
+}
+
 pub enum PySubjectRef<'a> {
     NamedNode(PyRef<'a, PyNamedNode>),
     BlankNode(PyRef<'a, PyBlankNode>),
+    Triple(PyRef<'a, PyTriple>),
 }
 
 impl<'a> From<&'a PySubjectRef<'a>> for SubjectRef<'a> {
@@ -953,6 +1030,7 @@ impl<'a> From<&'a PySubjectRef<'a>> for SubjectRef<'a> {
         match value {
             PySubjectRef::NamedNode(value) => value.inner.as_ref().into(),
             PySubjectRef::BlankNode(value) => value.inner.as_ref().into(),
+            PySubjectRef::Triple(value) => (&value.inner).into(),
         }
     }
 }
@@ -965,6 +1043,8 @@ impl<'a> TryFrom<&'a PyAny> for PySubjectRef<'a> {
             Ok(Self::NamedNode(node.borrow()))
         } else if let Ok(node) = value.downcast::<PyCell<PyBlankNode>>() {
             Ok(Self::BlankNode(node.borrow()))
+        } else if let Ok(node) = value.downcast::<PyCell<PyTriple>>() {
+            Ok(Self::Triple(node.borrow()))
         } else {
             Err(PyTypeError::new_err(format!(
                 "{} is not an RDF named or blank node",
@@ -978,6 +1058,7 @@ pub enum PyTermRef<'a> {
     NamedNode(PyRef<'a, PyNamedNode>),
     BlankNode(PyRef<'a, PyBlankNode>),
     Literal(PyRef<'a, PyLiteral>),
+    Triple(PyRef<'a, PyTriple>),
 }
 
 impl<'a> From<&'a PyTermRef<'a>> for TermRef<'a> {
@@ -986,6 +1067,7 @@ impl<'a> From<&'a PyTermRef<'a>> for TermRef<'a> {
             PyTermRef::NamedNode(value) => value.inner.as_ref().into(),
             PyTermRef::BlankNode(value) => value.inner.as_ref().into(),
             PyTermRef::Literal(value) => value.inner.as_ref().into(),
+            PyTermRef::Triple(value) => (&value.inner).into(),
         }
     }
 }
@@ -1006,6 +1088,8 @@ impl<'a> TryFrom<&'a PyAny> for PyTermRef<'a> {
             Ok(Self::BlankNode(node.borrow()))
         } else if let Ok(node) = value.downcast::<PyCell<PyLiteral>>() {
             Ok(Self::Literal(node.borrow()))
+        } else if let Ok(node) = value.downcast::<PyCell<PyTriple>>() {
+            Ok(Self::Triple(node.borrow()))
         } else {
             Err(PyTypeError::new_err(format!(
                 "{} is not an RDF term",
diff --git a/python/src/sparql.rs b/python/src/sparql.rs
index e0173d83..b79fb756 100644
--- a/python/src/sparql.rs
+++ b/python/src/sparql.rs
@@ -50,7 +50,7 @@ pub fn parse_query(
         query.dataset_mut().set_available_named_graphs(
             named_graphs
                 .iter()?
-                .map(|graph| Ok(graph?.extract::<PySubject>()?.into()))
+                .map(|graph| Ok(graph?.extract::<PyNamedOrBlankNode>()?.into()))
                 .collect::<PyResult<_>>()?,
         )
     }
diff --git a/python/src/store.rs b/python/src/store.rs
index 4a8c9295..b815e6fd 100644
--- a/python/src/store.rs
+++ b/python/src/store.rs
@@ -385,11 +385,11 @@ impl PyStore {
             PyGraphNameRef::DefaultGraph => Ok(()),
             PyGraphNameRef::NamedNode(graph_name) => self
                 .inner
-                .insert_named_graph(&PySubjectRef::NamedNode(graph_name))
+                .insert_named_graph(&PyNamedOrBlankNodeRef::NamedNode(graph_name))
                 .map(|_| ()),
             PyGraphNameRef::BlankNode(graph_name) => self
                 .inner
-                .insert_named_graph(&PySubjectRef::BlankNode(graph_name))
+                .insert_named_graph(&PyNamedOrBlankNodeRef::BlankNode(graph_name))
                 .map(|_| ()),
         }
         .map_err(map_io_err)
@@ -414,11 +414,11 @@ impl PyStore {
             PyGraphNameRef::DefaultGraph => self.inner.clear_graph(GraphNameRef::DefaultGraph),
             PyGraphNameRef::NamedNode(graph_name) => self
                 .inner
-                .remove_named_graph(&PySubjectRef::NamedNode(graph_name))
+                .remove_named_graph(&PyNamedOrBlankNodeRef::NamedNode(graph_name))
                 .map(|_| ()),
             PyGraphNameRef::BlankNode(graph_name) => self
                 .inner
-                .remove_named_graph(&PySubjectRef::BlankNode(graph_name))
+                .remove_named_graph(&PyNamedOrBlankNodeRef::BlankNode(graph_name))
                 .map(|_| ()),
         }
         .map_err(map_io_err)?;
@@ -487,7 +487,7 @@ impl PyIterProtocol for GraphNameIter {
         slf.into()
     }
 
-    fn __next__(mut slf: PyRefMut<Self>) -> PyResult<Option<PySubject>> {
+    fn __next__(mut slf: PyRefMut<Self>) -> PyResult<Option<PyNamedOrBlankNode>> {
         slf.inner
             .next()
             .map(|q| Ok(q.map_err(map_io_err)?.into()))
diff --git a/server/src/main.rs b/server/src/main.rs
index 366ef6ab..1e03256e 100644
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -21,7 +21,7 @@ use http_types::{
     StatusCode,
 };
 use oxigraph::io::{DatasetFormat, GraphFormat};
-use oxigraph::model::{GraphName, GraphNameRef, NamedNode, Subject};
+use oxigraph::model::{GraphName, GraphNameRef, NamedNode, NamedOrBlankNode};
 use oxigraph::sparql::{Query, QueryResults, QueryResultsFormat, Update};
 use oxigraph::store::Store;
 use oxiri::Iri;
@@ -407,7 +407,7 @@ fn evaluate_sparql_query(
     let named_graph_uris = named_graph_uris
         .into_iter()
         .map(|e| Ok(NamedNode::new(e)?.into()))
-        .collect::<Result<Vec<Subject>>>()
+        .collect::<Result<Vec<NamedOrBlankNode>>>()
         .map_err(bad_request)?;
 
     if !default_graph_uris.is_empty() || !named_graph_uris.is_empty() {
@@ -490,7 +490,7 @@ fn evaluate_sparql_update(
     let named_graph_uris = named_graph_uris
         .into_iter()
         .map(|e| Ok(NamedNode::new(e)?.into()))
-        .collect::<Result<Vec<Subject>>>()
+        .collect::<Result<Vec<NamedOrBlankNode>>>()
         .map_err(bad_request)?;
     if !default_graph_uris.is_empty() || !named_graph_uris.is_empty() {
         for using in update.using_datasets_mut() {
diff --git a/testsuite/src/sparql_evaluator.rs b/testsuite/src/sparql_evaluator.rs
index 1aa5a66c..5ac05e12 100644
--- a/testsuite/src/sparql_evaluator.rs
+++ b/testsuite/src/sparql_evaluator.rs
@@ -113,7 +113,7 @@ fn evaluate_evaluation_test(test: &Test) -> Result<()> {
                     }
                 }
                 for graph_name in query.dataset().available_named_graphs().unwrap_or(&[]) {
-                    if let Subject::NamedNode(graph_name) = graph_name {
+                    if let NamedOrBlankNode::NamedNode(graph_name) = graph_name {
                         load_to_store(graph_name.as_str(), &store, graph_name.as_ref())?;
                     } else {
                         return Err(anyhow!(
diff --git a/wikibase/src/main.rs b/wikibase/src/main.rs
index 10e867ab..3f06019f 100644
--- a/wikibase/src/main.rs
+++ b/wikibase/src/main.rs
@@ -21,7 +21,7 @@ use http_types::{
     StatusCode,
 };
 use oxigraph::io::GraphFormat;
-use oxigraph::model::{GraphName, NamedNode, Subject};
+use oxigraph::model::{GraphName, NamedNode, NamedOrBlankNode};
 use oxigraph::sparql::{Query, QueryResults, QueryResultsFormat};
 use oxigraph::store::Store;
 use std::str::FromStr;
@@ -202,7 +202,7 @@ fn evaluate_sparql_query(
     let named_graph_uris = named_graph_uris
         .into_iter()
         .map(|e| Ok(NamedNode::new(e)?.into()))
-        .collect::<Result<Vec<Subject>>>()
+        .collect::<Result<Vec<NamedOrBlankNode>>>()
         .map_err(bad_request)?;
 
     if !default_graph_uris.is_empty() || !named_graph_uris.is_empty() {