diff --git a/src/main/java/de/ids_mannheim/korap/query/SpanClassQuery.java b/src/main/java/de/ids_mannheim/korap/query/SpanClassQuery.java
index a045e5f..16730ce 100644
--- a/src/main/java/de/ids_mannheim/korap/query/SpanClassQuery.java
+++ b/src/main/java/de/ids_mannheim/korap/query/SpanClassQuery.java
@@ -65,7 +65,8 @@
 
     @Override
     public Spans getSpans (final AtomicReaderContext context,
-			   Bits acceptDocs, Map<Term,TermContext> termContexts) throws IOException {
+			   Bits acceptDocs,
+			   Map<Term,TermContext> termContexts) throws IOException {
 	return (Spans) new ClassSpans(
 	    this.highlight,
 	    context,
@@ -105,7 +106,7 @@
 
     /** Returns true iff <code>o</code> is equal to this. */
     @Override
-    public boolean equals(Object o) {
+    public boolean equals (Object o) {
 	if (this == o) return true;
 	if (!(o instanceof SpanClassQuery)) return false;
 	
diff --git a/src/main/java/de/ids_mannheim/korap/query/spans/ClassSpans.java b/src/main/java/de/ids_mannheim/korap/query/spans/ClassSpans.java
index 1838f2e..6de3fb7 100644
--- a/src/main/java/de/ids_mannheim/korap/query/spans/ClassSpans.java
+++ b/src/main/java/de/ids_mannheim/korap/query/spans/ClassSpans.java
@@ -24,13 +24,20 @@
     private Collection<byte[]> payload;
     private final Spans spans;
     private byte number;
-    private ByteBuffer bb;
     private SpanQuery highlight;
     private Boolean hasmorespans = false;
 
-    private final Logger log = LoggerFactory.getLogger(ClassSpans.class);
+    private ByteBuffer bb = ByteBuffer.allocate(9);
 
-    public ClassSpans (SpanQuery highlight, AtomicReaderContext context, Bits acceptDocs, Map<Term,TermContext> termContexts, byte number) throws IOException {
+    private final static Logger log = LoggerFactory.getLogger(ClassSpans.class);
+    // This advices the java compiler to ignore all loggings
+    public static final boolean DEBUG = false;
+
+    public ClassSpans (SpanQuery highlight,
+		       AtomicReaderContext context,
+		       Bits acceptDocs,
+		       Map<Term,TermContext> termContexts,
+		       byte number) throws IOException {
 	spans = highlight.getSpans(context, acceptDocs, termContexts);
 	this.number = number;
 	this.highlight = highlight;
@@ -39,18 +46,11 @@
 
     @Override
     public Collection<byte[]> getPayload() throws IOException {
-	/*
-	for (byte[] x: highlightedPayload) {
-	    ByteBuffer b = ByteBuffer.wrap(x, 0, x.length);
-	    log.trace(">> Get Payload: {}-{} in class {}", b.getInt(), b.getInt(), b.get());
-	};
-	*/
 	return highlightedPayload;
     };
 
     @Override
     public boolean isPayloadAvailable() {
-	// return highlightedPayload.isEmpty() == false;
 	return true;
     };
 
@@ -68,7 +68,8 @@
     // inherit javadocs
     @Override
     public boolean next() throws IOException {
-	log.trace("Forward next");
+	if (DEBUG)
+	    log.trace("Forward next");
 
 	if (spans.next()) {
 	    hasmorespans = true;
@@ -77,22 +78,34 @@
 
 	    if (spans.isPayloadAvailable()) {
 		highlightedPayload.addAll(spans.getPayload());
-		log.trace("Found payload");
+		if (DEBUG)
+		    log.trace("Found payload");
 	    };
 
-
-	    log.trace("Start to create class {} with span {} - {}",
-		      number,
-		      spans.start(),
-		      spans.end());
+	    if (DEBUG)
+		log.trace("Start to create class {} with span {} - {}",
+			  number,
+			  spans.start(),
+			  spans.end());
 
 	    // Todo: Better allocate using a Factory!
 
-	    bb = ByteBuffer.allocate(9);
-
+	    //private
+	    bb.clear();
 	    bb.putInt(spans.start()).putInt(spans.end()).put(number);
+	    /*
+	    if (DEBUG)
+		log.trace("Results in {} with {}", bb.toString(), bb.array());
+	    */
 	    // Add highlight information as byte after offsets
 	    highlightedPayload.add(bb.array());
+	    /*
+	    if (DEBUG) {
+		bb.rewind();
+		log.trace("That was a class from {}-{} of class {}", bb.getInt(), bb.getInt(), bb.get());
+	    };
+	    */
+		
 	    return true;
 	};
 	hasmorespans = false;
@@ -102,6 +115,7 @@
     // inherit javadocs
     @Override
     public boolean skipTo(int target) throws IOException {
+	highlightedPayload.clear();
 	if (hasmorespans && spans.doc() < target)
 	    return spans.skipTo(target);
 	return false;
diff --git a/src/main/java/de/ids_mannheim/korap/query/spans/ElementSpans.java b/src/main/java/de/ids_mannheim/korap/query/spans/ElementSpans.java
index a44ed49..531b927 100644
--- a/src/main/java/de/ids_mannheim/korap/query/spans/ElementSpans.java
+++ b/src/main/java/de/ids_mannheim/korap/query/spans/ElementSpans.java
@@ -27,10 +27,6 @@
  */
 public class ElementSpans extends Spans {
 
-    // This advices the java compiler to ignore all loggings
-    public static final boolean DEBUG = false;
-  
-
     private byte[] payloadByte = new byte[4];
     private ByteBuffer bb = ByteBuffer.allocate(4);
 
@@ -46,6 +42,8 @@
     private KorapTermSpan overflow, tempSpan;
 
     private final static Logger log = LoggerFactory.getLogger(ElementSpans.class);
+    // This advices the java compiler to ignore all loggings
+    public static final boolean DEBUG = false;
 
 
     /**
diff --git a/src/test/java/de/ids_mannheim/korap/benchmark/TestBenchmarkSpans.java b/src/test/java/de/ids_mannheim/korap/benchmark/TestBenchmarkSpans.java
index d177eb3..c1b2d1c 100644
--- a/src/test/java/de/ids_mannheim/korap/benchmark/TestBenchmarkSpans.java
+++ b/src/test/java/de/ids_mannheim/korap/benchmark/TestBenchmarkSpans.java
@@ -23,7 +23,7 @@
 import org.junit.runners.JUnit4;
 
 @RunWith(JUnit4.class)
-public class TestBenchmarkElementSpans {
+public class TestBenchmarkSpans {
 
     @Test
     public void checkBenchmark1 () throws IOException {
@@ -152,6 +152,80 @@
 
     
     @Test
+    public void checkBenchmarkClasses () throws IOException {
+	// [orth=Der]{1:[orth=Mann]{2:[orth=und]}}
+
+	Properties prop = new Properties();
+	InputStream fr = new FileInputStream(getClass().getResource("/korap.conf").getFile());
+	prop.load(fr);
+
+	// Get the real index
+	KorapIndex ki = new KorapIndex(new MMapDirectory(new File(prop.getProperty("lucene.indexDir"))));
+
+	// Create a container for virtual collections:
+	KorapCollection kc = new KorapCollection(ki);
+
+	long t1 = 0, t2 = 0;
+	// Without classes
+	String json = getString(getClass().getResource("/queries/benchmark5-ohne.jsonld").getFile());
+
+	int rounds = 2000;
+
+	KorapResult kr = new KorapResult();
+
+	t1 = System.nanoTime();
+	for (int i = 1; i <= rounds; i++) {
+	    kr = new KorapSearch(json).run(ki);
+	};
+	t2 = System.nanoTime();
+
+	double seconds = (double)(t2-t1) / 1000000000.0;
+	
+	System.out.println("It took " + seconds + " seconds without classes");
+
+	t1 = 0;
+	t2 = 0;
+	// With classes
+	json = getString(getClass().getResource("/queries/benchmark5.jsonld").getFile());
+
+	t1 = System.nanoTime();
+	for (int i = 1; i <= rounds; i++) {
+	    kr = new KorapSearch(json).run(ki);
+	};
+	t2 = System.nanoTime();
+
+	seconds = (double)(t2-t1) / 1000000000.0;
+	
+	System.out.println("It took " + seconds + " seconds with classes");
+
+
+	// System.err.println(kr.toJSON());
+
+	System.err.println(kr.getMatch(3).getSnippetBrackets());
+
+
+	// 2000 rounds:
+	// It took 10.872934435 seconds without classes
+	// It took 22.581117396 seconds with classes
+
+	// It took 10.703933598 seconds without classes
+	// It took 19.354674517 seconds with classes
+
+	// It took 10.939948726 seconds without classes
+	// It took 16.998470662 seconds with classes
+
+	// It took 10.900975837 seconds without classes
+	// It took 14.902590949 seconds with classes
+
+	// It took 10.365989238 seconds without classes
+	// It took 13.833405885 seconds with classes
+
+    };
+
+
+
+    
+    @Test
     public void checkBenchmarkIndexDocuments () throws IOException {
 	long t1 = 0, t2 = 0;
 
diff --git a/src/test/java/de/ids_mannheim/korap/index/TestFieldDocument.java b/src/test/java/de/ids_mannheim/korap/index/TestFieldDocument.java
index 0127a65..bb2ff5f 100644
--- a/src/test/java/de/ids_mannheim/korap/index/TestFieldDocument.java
+++ b/src/test/java/de/ids_mannheim/korap/index/TestFieldDocument.java
@@ -187,6 +187,11 @@
 	System.err.println(kr.toJSON());
 	*/
 
+
+	kr = ki.search(query, 0, (short) 1, true, (short) 2, false, (short) 5);
+	assertEquals("... Buchstabe des [{1:{2:lateinischen} Alphabets}] und  ...", kr.match(0).getSnippetBrackets());
+
+	
 	kr = ki.search(query, 0, (short) 50, true, (short) 2, false, (short) 5);
 
 //	System.err.println(kr.toJSON());
diff --git a/src/test/resources/queries/benchmark5-ohne.jsonld b/src/test/resources/queries/benchmark5-ohne.jsonld
new file mode 100644
index 0000000..725be7a
--- /dev/null
+++ b/src/test/resources/queries/benchmark5-ohne.jsonld
@@ -0,0 +1,33 @@
+{
+    "@context" : "http://ids-mannheim.de/ns/KorAP/json-ld/v0.1/context.jsonld",
+    "query": {
+	"@type": "korap:group", 
+	"operation": "operation:sequence",
+	"operands": [
+	    {
+		"@type": "korap:token",
+		"wrap" : {
+		    "@type": "korap:term", 
+		    "layer": "orth",
+		    "key" : "der"
+		}
+	    },
+	    {
+		"@type": "korap:token",
+		"wrap" : {
+		    "@type": "korap:term", 
+		    "layer": "orth",
+		    "key" : "Mann"
+		}
+	    },
+	    {
+		"@type": "korap:token",
+		"wrap" : {
+		    "@type": "korap:term", 
+		    "layer": "orth",
+		    "key" : "und"
+		}
+	    }
+	]
+    }
+}
diff --git a/src/test/resources/queries/benchmark5.jsonld b/src/test/resources/queries/benchmark5.jsonld
new file mode 100644
index 0000000..332d23f
--- /dev/null
+++ b/src/test/resources/queries/benchmark5.jsonld
@@ -0,0 +1,54 @@
+{
+    "@context" : "http://ids-mannheim.de/ns/KorAP/json-ld/v0.1/context.jsonld",
+    "query": {
+	"@type": "korap:group", 
+	"operation": "operation:sequence",
+	"operands": [
+	    {
+		"@type": "korap:token",
+		"wrap" : {
+		    "@type": "korap:term", 
+		    "layer": "orth",
+		    "key" : "der"
+		}
+	    },
+	    {
+		"@type" : "korap:group",
+		"operation" : "operation:class",
+		"class" : 1,
+		"operands" : [
+		    {
+			"@type": "korap:group", 
+			"operation": "operation:sequence",
+			"operands" : [
+			    {
+				"@type": "korap:token",
+				"wrap" : {
+				    "@type": "korap:term", 
+				    "layer": "orth",
+				    "key" : "Mann"
+				}
+			    },
+			    {
+				"@type" : "korap:group",
+				"operation" : "operation:class",
+				"class" : 2,
+				"operands" : [
+				    {
+					"@type": "korap:token",
+					"wrap" : {
+					    "@type": "korap:term", 
+					    "layer": "orth",
+					    "key" : "und"
+					}
+				    }
+				]
+			    }
+			    
+			]
+		    }
+		]
+	    }
+	]
+    }
+}