diff --git a/lib/oxrdfio/src/parser.rs b/lib/oxrdfio/src/parser.rs
index 4c7090b6..25f86598 100644
--- a/lib/oxrdfio/src/parser.rs
+++ b/lib/oxrdfio/src/parser.rs
@@ -53,6 +53,7 @@ use tokio::io::AsyncRead;
 /// assert_eq!(quads[0].subject.to_string(), "<http://example.com/s>");
 /// # std::io::Result::Ok(())
 /// ```
+#[must_use]
 pub struct RdfParser {
     inner: RdfParserKind,
     default_graph: GraphName,
@@ -72,7 +73,6 @@ enum RdfParserKind {
 impl RdfParser {
     /// Builds a parser for the given format.
     #[inline]
-    #[must_use]
     pub fn from_format(format: RdfFormat) -> Self {
         Self {
             inner: match format {
@@ -172,7 +172,6 @@ impl RdfParser {
     /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
     /// ```
     #[inline]
-    #[must_use]
     pub fn with_default_graph(self, default_graph: impl Into<GraphName>) -> Self {
         Self {
             inner: self.inner,
@@ -195,7 +194,6 @@ impl RdfParser {
     /// assert!(parser.parse_read(file.as_bytes()).next().unwrap().is_err());
     /// ```
     #[inline]
-    #[must_use]
     pub fn without_named_graphs(self) -> Self {
         Self {
             inner: self.inner,
@@ -224,7 +222,6 @@ impl RdfParser {
     /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
     /// ```
     #[inline]
-    #[must_use]
     pub fn rename_blank_nodes(self) -> Self {
         Self {
             inner: self.inner,
diff --git a/lib/oxrdfio/src/serializer.rs b/lib/oxrdfio/src/serializer.rs
index 26229e5d..6289ed28 100644
--- a/lib/oxrdfio/src/serializer.rs
+++ b/lib/oxrdfio/src/serializer.rs
@@ -48,6 +48,7 @@ use tokio::io::AsyncWrite;
 /// assert_eq!(buffer.as_slice(), "<http://example.com/s> <http://example.com/p> <http://example.com/o> <http://example.com/g> .\n".as_bytes());
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
+#[must_use]
 pub struct RdfSerializer {
     format: RdfFormat,
 }
diff --git a/lib/oxrdfxml/src/parser.rs b/lib/oxrdfxml/src/parser.rs
index a17f9ca4..747b2419 100644
--- a/lib/oxrdfxml/src/parser.rs
+++ b/lib/oxrdfxml/src/parser.rs
@@ -50,6 +50,7 @@ use tokio::io::{AsyncRead, BufReader as AsyncBufReader};
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
 #[derive(Default)]
+#[must_use]
 pub struct RdfXmlParser {
     base: Option<Iri<String>>,
 }
@@ -188,6 +189,7 @@ impl RdfXmlParser {
 /// assert_eq!(2, count);
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
+#[must_use]
 pub struct FromReadRdfXmlReader<R: Read> {
     results: Vec<Triple>,
     reader: RdfXmlReader<BufReader<R>>,
@@ -259,6 +261,7 @@ impl<R: Read> FromReadRdfXmlReader<R> {
 /// }
 /// ```
 #[cfg(feature = "async-tokio")]
+#[must_use]
 pub struct FromTokioAsyncReadRdfXmlReader<R: AsyncRead + Unpin> {
     results: Vec<Triple>,
     reader: RdfXmlReader<AsyncBufReader<R>>,
diff --git a/lib/oxrdfxml/src/serializer.rs b/lib/oxrdfxml/src/serializer.rs
index e3d93065..d3e9949f 100644
--- a/lib/oxrdfxml/src/serializer.rs
+++ b/lib/oxrdfxml/src/serializer.rs
@@ -27,6 +27,7 @@ use tokio::io::AsyncWrite;
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
 #[derive(Default)]
+#[must_use]
 pub struct RdfXmlSerializer;
 
 impl RdfXmlSerializer {
@@ -123,6 +124,7 @@ impl RdfXmlSerializer {
 /// );
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
+#[must_use]
 pub struct ToWriteRdfXmlWriter<W: Write> {
     writer: Writer<W>,
     inner: InnerRdfXmlWriter,
@@ -176,6 +178,7 @@ impl<W: Write> ToWriteRdfXmlWriter<W> {
 /// }
 /// ```
 #[cfg(feature = "async-tokio")]
+#[must_use]
 pub struct ToTokioAsyncWriteRdfXmlWriter<W: AsyncWrite + Unpin> {
     writer: Writer<W>,
     inner: InnerRdfXmlWriter,
diff --git a/lib/oxttl/src/n3.rs b/lib/oxttl/src/n3.rs
index 0edb9d13..14c58413 100644
--- a/lib/oxttl/src/n3.rs
+++ b/lib/oxttl/src/n3.rs
@@ -204,6 +204,7 @@ impl From<Quad> for N3Quad {
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
 #[derive(Default)]
+#[must_use]
 pub struct N3Parser {
     base: Option<Iri<String>>,
     prefixes: HashMap<String, Iri<String>>,
@@ -376,6 +377,7 @@ impl N3Parser {
 /// assert_eq!(2, count);
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
+#[must_use]
 pub struct FromReadN3Reader<R: Read> {
     inner: FromReadIterator<R, N3Recognizer>,
 }
@@ -420,6 +422,7 @@ impl<R: Read> Iterator for FromReadN3Reader<R> {
 /// }
 /// ```
 #[cfg(feature = "async-tokio")]
+#[must_use]
 pub struct FromTokioAsyncReadN3Reader<R: AsyncRead + Unpin> {
     inner: FromTokioAsyncReadIterator<R, N3Recognizer>,
 }
diff --git a/lib/oxttl/src/nquads.rs b/lib/oxttl/src/nquads.rs
index 71ac2d4c..caa7c642 100644
--- a/lib/oxttl/src/nquads.rs
+++ b/lib/oxttl/src/nquads.rs
@@ -35,6 +35,7 @@ use tokio::io::{AsyncRead, AsyncWrite, AsyncWriteExt};
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
 #[derive(Default)]
+#[must_use]
 pub struct NQuadsParser {
     #[cfg(feature = "rdf-star")]
     with_quoted_triples: bool,
@@ -50,7 +51,6 @@ impl NQuadsParser {
     /// Enables [N-Quads-star](https://w3c.github.io/rdf-star/cg-spec/2021-12-17.html#n-quads-star).
     #[cfg(feature = "rdf-star")]
     #[inline]
-    #[must_use]
     pub fn with_quoted_triples(mut self) -> Self {
         self.with_quoted_triples = true;
         self
@@ -193,6 +193,7 @@ impl NQuadsParser {
 /// assert_eq!(2, count);
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
+#[must_use]
 pub struct FromReadNQuadsReader<R: Read> {
     inner: FromReadIterator<R, NQuadsRecognizer>,
 }
@@ -233,6 +234,7 @@ impl<R: Read> Iterator for FromReadNQuadsReader<R> {
 /// }
 /// ```
 #[cfg(feature = "async-tokio")]
+#[must_use]
 pub struct FromTokioAsyncReadNQuadsReader<R: AsyncRead + Unpin> {
     inner: FromTokioAsyncReadIterator<R, NQuadsRecognizer>,
 }
@@ -334,6 +336,7 @@ impl LowLevelNQuadsReader {
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
 #[derive(Default)]
+#[must_use]
 pub struct NQuadsSerializer;
 
 impl NQuadsSerializer {
@@ -449,6 +452,7 @@ impl NQuadsSerializer {
 /// );
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
+#[must_use]
 pub struct ToWriteNQuadsWriter<W: Write> {
     write: W,
     writer: LowLevelNQuadsWriter,
@@ -490,6 +494,7 @@ impl<W: Write> ToWriteNQuadsWriter<W> {
 /// }
 /// ```
 #[cfg(feature = "async-tokio")]
+#[must_use]
 pub struct ToTokioAsyncWriteNQuadsWriter<W: AsyncWrite + Unpin> {
     write: W,
     writer: LowLevelNQuadsWriter,
diff --git a/lib/oxttl/src/ntriples.rs b/lib/oxttl/src/ntriples.rs
index 07672f1a..f8c32b12 100644
--- a/lib/oxttl/src/ntriples.rs
+++ b/lib/oxttl/src/ntriples.rs
@@ -36,6 +36,7 @@ use tokio::io::{AsyncRead, AsyncWrite, AsyncWriteExt};
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
 #[derive(Default)]
+#[must_use]
 pub struct NTriplesParser {
     #[cfg(feature = "rdf-star")]
     with_quoted_triples: bool,
@@ -51,7 +52,6 @@ impl NTriplesParser {
     /// Enables [N-Triples-star](https://w3c.github.io/rdf-star/cg-spec/2021-12-17.html#n-triples-star).
     #[cfg(feature = "rdf-star")]
     #[inline]
-    #[must_use]
     pub fn with_quoted_triples(mut self) -> Self {
         self.with_quoted_triples = true;
         self
@@ -194,6 +194,7 @@ impl NTriplesParser {
 /// assert_eq!(2, count);
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
+#[must_use]
 pub struct FromReadNTriplesReader<R: Read> {
     inner: FromReadIterator<R, NQuadsRecognizer>,
 }
@@ -234,6 +235,7 @@ impl<R: Read> Iterator for FromReadNTriplesReader<R> {
 /// }
 /// ```
 #[cfg(feature = "async-tokio")]
+#[must_use]
 pub struct FromTokioAsyncReadNTriplesReader<R: AsyncRead + Unpin> {
     inner: FromTokioAsyncReadIterator<R, NQuadsRecognizer>,
 }
@@ -334,6 +336,7 @@ impl LowLevelNTriplesReader {
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
 #[derive(Default)]
+#[must_use]
 pub struct NTriplesSerializer;
 
 impl NTriplesSerializer {
@@ -445,6 +448,7 @@ impl NTriplesSerializer {
 /// );
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
+#[must_use]
 pub struct ToWriteNTriplesWriter<W: Write> {
     write: W,
     writer: LowLevelNTriplesWriter,
@@ -485,6 +489,7 @@ impl<W: Write> ToWriteNTriplesWriter<W> {
 /// }
 /// ```
 #[cfg(feature = "async-tokio")]
+#[must_use]
 pub struct ToTokioAsyncWriteNTriplesWriter<W: AsyncWrite + Unpin> {
     write: W,
     writer: LowLevelNTriplesWriter,
diff --git a/lib/oxttl/src/trig.rs b/lib/oxttl/src/trig.rs
index f2c24ca0..6dfb2b43 100644
--- a/lib/oxttl/src/trig.rs
+++ b/lib/oxttl/src/trig.rs
@@ -40,6 +40,7 @@ use tokio::io::{AsyncRead, AsyncWrite, AsyncWriteExt};
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
 #[derive(Default)]
+#[must_use]
 pub struct TriGParser {
     base: Option<Iri<String>>,
     prefixes: HashMap<String, Iri<String>>,
@@ -74,7 +75,6 @@ impl TriGParser {
     /// Enables [TriG-star](https://w3c.github.io/rdf-star/cg-spec/2021-12-17.html#trig-star).
     #[cfg(feature = "rdf-star")]
     #[inline]
-    #[must_use]
     pub fn with_quoted_triples(mut self) -> Self {
         self.with_quoted_triples = true;
         self
@@ -224,6 +224,7 @@ impl TriGParser {
 /// assert_eq!(2, count);
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
+#[must_use]
 pub struct FromReadTriGReader<R: Read> {
     inner: FromReadIterator<R, TriGRecognizer>,
 }
@@ -266,6 +267,7 @@ impl<R: Read> Iterator for FromReadTriGReader<R> {
 /// }
 /// ```
 #[cfg(feature = "async-tokio")]
+#[must_use]
 pub struct FromTokioAsyncReadTriGReader<R: AsyncRead + Unpin> {
     inner: FromTokioAsyncReadIterator<R, TriGRecognizer>,
 }
@@ -367,6 +369,7 @@ impl LowLevelTriGReader {
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
 #[derive(Default)]
+#[must_use]
 pub struct TriGSerializer;
 
 impl TriGSerializer {
@@ -486,6 +489,7 @@ impl TriGSerializer {
 /// );
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
+#[must_use]
 pub struct ToWriteTriGWriter<W: Write> {
     write: W,
     writer: LowLevelTriGWriter,
@@ -528,6 +532,7 @@ impl<W: Write> ToWriteTriGWriter<W> {
 /// }
 /// ```
 #[cfg(feature = "async-tokio")]
+#[must_use]
 pub struct ToTokioAsyncWriteTriGWriter<W: AsyncWrite + Unpin> {
     write: W,
     writer: LowLevelTriGWriter,
diff --git a/lib/oxttl/src/turtle.rs b/lib/oxttl/src/turtle.rs
index 70be2806..133c9cca 100644
--- a/lib/oxttl/src/turtle.rs
+++ b/lib/oxttl/src/turtle.rs
@@ -42,6 +42,7 @@ use tokio::io::{AsyncRead, AsyncWrite};
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
 #[derive(Default)]
+#[must_use]
 pub struct TurtleParser {
     base: Option<Iri<String>>,
     prefixes: HashMap<String, Iri<String>>,
@@ -76,7 +77,6 @@ impl TurtleParser {
     /// Enables [Turtle-star](https://w3c.github.io/rdf-star/cg-spec/2021-12-17.html#turtle-star).
     #[cfg(feature = "rdf-star")]
     #[inline]
-    #[must_use]
     pub fn with_quoted_triples(mut self) -> Self {
         self.with_quoted_triples = true;
         self
@@ -226,6 +226,7 @@ impl TurtleParser {
 /// assert_eq!(2, count);
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
+#[must_use]
 pub struct FromReadTurtleReader<R: Read> {
     inner: FromReadIterator<R, TriGRecognizer>,
 }
@@ -268,6 +269,7 @@ impl<R: Read> Iterator for FromReadTurtleReader<R> {
 /// }
 /// ```
 #[cfg(feature = "async-tokio")]
+#[must_use]
 pub struct FromTokioAsyncReadTurtleReader<R: AsyncRead + Unpin> {
     inner: FromTokioAsyncReadIterator<R, TriGRecognizer>,
 }
@@ -368,6 +370,7 @@ impl LowLevelTurtleReader {
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
 #[derive(Default)]
+#[must_use]
 pub struct TurtleSerializer {
     inner: TriGSerializer,
 }
@@ -480,6 +483,7 @@ impl TurtleSerializer {
 /// );
 /// # Result::<_,Box<dyn std::error::Error>>::Ok(())
 /// ```
+#[must_use]
 pub struct ToWriteTurtleWriter<W: Write> {
     inner: ToWriteTriGWriter<W>,
 }
@@ -520,6 +524,7 @@ impl<W: Write> ToWriteTurtleWriter<W> {
 /// }
 /// ```
 #[cfg(feature = "async-tokio")]
+#[must_use]
 pub struct ToTokioAsyncWriteTurtleWriter<W: AsyncWrite + Unpin> {
     inner: ToTokioAsyncWriteTriGWriter<W>,
 }