diff --git a/src/main/java/de/ids_mannheim/korap/KorapIndex.java b/src/main/java/de/ids_mannheim/korap/KorapIndex.java
index 8b43b19..e2d957c 100644
--- a/src/main/java/de/ids_mannheim/korap/KorapIndex.java
+++ b/src/main/java/de/ids_mannheim/korap/KorapIndex.java
@@ -104,6 +104,13 @@
  * @author ndiewald
  */
 public class KorapIndex {
+
+    // Todo: Use configuration
+    // Last line of defense for simple DOS attacks!
+    private int maxTermRelations = 100;
+    private int autoCommit = 500;
+
+
     private Directory directory;
 
     // Temp:
@@ -114,12 +121,10 @@
     private IndexSearcher searcher;
     private boolean readerOpen = false;
     private int commitCounter = 0;
-    private int autoCommit = 500; // Todo: Use configuration
     private HashMap termContexts;
     private ObjectMapper mapper = new ObjectMapper();
     private String version;
 
-    private int maxTermRelations = 50;
 
     private static ByteBuffer bb       = ByteBuffer.allocate(4),
 	                      bbOffset = ByteBuffer.allocate(8),
diff --git a/src/main/java/de/ids_mannheim/korap/KorapMatch.java b/src/main/java/de/ids_mannheim/korap/KorapMatch.java
index dc28449..5d398b2 100644
--- a/src/main/java/de/ids_mannheim/korap/KorapMatch.java
+++ b/src/main/java/de/ids_mannheim/korap/KorapMatch.java
@@ -1084,6 +1084,9 @@
 	LinkedList<int[]> openList  = new LinkedList<int[]>();
 	LinkedList<int[]> closeList = new LinkedList<int[]>();
 
+	// Filter multiple identifier
+	this._filterMultipleIdentifiers();
+
 	// Add highlight spans to balance lists
 	openList.addAll(this.span);
 	closeList.addAll(this.span);
@@ -1272,6 +1275,14 @@
 	    if (DEBUG)
 		log.trace("There are highlights!");
 
+	    /*
+Here maybe?
+	if (this.highlight.last.start = hl.start && this.highlight.end == hl.end && this.highlight.id < -1) {
+	    return;
+	};
+	*/
+
+	    
 	    for (Highlight highlight : this.highlight) {
 		int start = this.positionsToOffset.start(
 		  ldid, highlight.start
@@ -1342,4 +1353,35 @@
 
 	return "{}";
     };
+
+
+    // Remove duplicate identifiers
+    // Yeah ... I mean ... why not?
+    private void _filterMultipleIdentifiers () {
+	ArrayList<Integer> removeDuplicate = new ArrayList<>(10);
+	HashSet<Integer> identifiers = new HashSet<>(20);
+	for (int i = 0; i < this.span.size(); i++) {
+	    // span is an int array: [Start, End, Number, Dummy]
+	    int highlightNumber = this.span.get(i)[2];
+
+	    // number is an identifier
+	    if (highlightNumber < -1) {
+		int idNumber = identifierNumber.get(highlightNumber);
+		if (identifiers.contains(idNumber)) {
+		    removeDuplicate.add(i);
+		}
+		else {
+		    identifiers.add(idNumber);
+		};
+	    };
+	};
+
+	Collections.sort(removeDuplicate);
+	Collections.reverse(removeDuplicate);
+
+	// Delete all duplicate identifiers
+	for (int delete : removeDuplicate) {
+	    this.span.remove(delete);
+	};
+    };
 };
diff --git a/src/main/resources/log4j.properties b/src/main/resources/log4j.properties
index f48fe94..af72c2d 100644
--- a/src/main/resources/log4j.properties
+++ b/src/main/resources/log4j.properties
@@ -10,7 +10,7 @@
 #log4j.logger.de.ids_mannheim.korap.query.spans.NextSpans = TRACE, stdout
 #log4j.logger.de.ids_mannheim.korap.query.spans.SimpleSpans = TRACE, stdout
 # log4j.logger.de.ids_mannheim.korap.query.spans.ClassSpans = TRACE, stdout
-#log4j.logger.de.ids_mannheim.korap.query.spans.MatchSpans = TRACE, stdout
+# log4j.logger.de.ids_mannheim.korap.query.spans.MatchSpans = TRACE, stdout
 
 # Collections
 #log4j.logger.de.ids_mannheim.korap.KorapFilter = TRACE, stdout