diff --git a/commons-rdf-simple/src/main/java/org/apache/commons/rdf/simple/experimental/AbstractRDFParser.java b/commons-rdf-simple/src/main/java/org/apache/commons/rdf/simple/experimental/AbstractRDFParser.java
index 51269aa5..5c6c1b40 100644
--- a/commons-rdf-simple/src/main/java/org/apache/commons/rdf/simple/experimental/AbstractRDFParser.java
+++ b/commons-rdf-simple/src/main/java/org/apache/commons/rdf/simple/experimental/AbstractRDFParser.java
@@ -206,13 +206,13 @@ public Optional<IRI> getSourceIri() {
         return Optional.ofNullable(sourceIri);
     }
 
-    private RDF rdfTermFactory = null;
-    private RDFSyntax contentTypeSyntax = null;
-    private String contentType = null;
-    private IRI base = null;
-    private InputStream sourceInputStream = null;
-    private Path sourceFile = null;
-    private IRI sourceIri = null;
+    private RDF rdfTermFactory;
+    private RDFSyntax contentTypeSyntax;
+    private String contentType;
+    private IRI base;
+    private InputStream sourceInputStream;
+    private Path sourceFile;
+    private IRI sourceIri;
     private Consumer<Quad> target;
     private Dataset targetDataset;
     private Graph targetGraph;