diff --git a/src/main/java/de/ids_mannheim/korap/KrillIndex.java b/src/main/java/de/ids_mannheim/korap/KrillIndex.java
index 7829387..6a7e495 100644
--- a/src/main/java/de/ids_mannheim/korap/KrillIndex.java
+++ b/src/main/java/de/ids_mannheim/korap/KrillIndex.java
@@ -412,7 +412,7 @@
         try {
 
             // Add document to writer
-            this.writer().addDocument(doc.doc);
+            this.writer().addDocument(doc.compile());
             if (++commitCounter > autoCommit) {
                 this.commit();
                 commitCounter = 0;
diff --git a/src/main/java/de/ids_mannheim/korap/index/AbstractDocument.java b/src/main/java/de/ids_mannheim/korap/index/AbstractDocument.java
index e579a16..fb467ff 100644
--- a/src/main/java/de/ids_mannheim/korap/index/AbstractDocument.java
+++ b/src/main/java/de/ids_mannheim/korap/index/AbstractDocument.java
@@ -460,6 +460,27 @@
                 )
             );
     };
+
+
+    @JsonIgnore
+    public void addInt (String key, String value) {
+        if (value == null)
+            return;
+        
+        mFields.add(
+            new MetaField(
+                key,
+                "type:integer",
+                value
+                )
+            );
+    };
+
+    @JsonIgnore
+    public void addInt (String key, int value) {
+        this.addInt(key, new Integer(value).toString());
+    };
+
     
     @JsonIgnore
     public void addStored (String key, String value) {
@@ -474,6 +495,22 @@
                 )
             );
     };
+
+
+    @JsonIgnore
+    public void addAttachement (String key, String value) {
+        if (value == null)
+            return;
+
+        mFields.add(
+            new MetaField(
+                key,
+                "type:attachement",
+                value
+                )
+            );
+    };
+
     
     @JsonIgnore
     public void addKeywords (String key, String value) {
diff --git a/src/main/java/de/ids_mannheim/korap/index/FieldDocument.java b/src/main/java/de/ids_mannheim/korap/index/FieldDocument.java
index b6b3292..4ca1ae6 100644
--- a/src/main/java/de/ids_mannheim/korap/index/FieldDocument.java
+++ b/src/main/java/de/ids_mannheim/korap/index/FieldDocument.java
@@ -87,123 +87,74 @@
     };
 
 
-    // see http://www.cowtowncoder.com/blog/archives/2011/07/entry_457.html
+    /**
+     * Add all fields to document
+     */
+    public Document compile () {
 
-    public void addInt (String key, int value) {
-        doc.add(new IntField(key, value, Field.Store.YES));
+		// Iterate over all fields
+		Iterator<MetaField> fIter = mFields.iterator();
+		while (fIter.hasNext()) {
+            MetaField mf = fIter.next();
+            switch (mf.type) {
+
+            case "type:integer":
+                try {
+                    int val = Integer.parseInt(mf.values.get(0));
+                    doc.add(new IntField(mf.key, val, Field.Store.YES));
+                }
+                catch (NumberFormatException ne) {
+                    continue;
+                };
+                break;
+
+            case "type:date":
+                KrillDate date = new KrillDate(mf.values.get(0));
+                if (date != null) {
+                    try {
+                        int dateInt = date.toInteger();
+                        doc.add(new IntField(mf.key, dateInt, Field.Store.YES));
+                    }
+                    catch (NumberFormatException ne) {
+                        continue;
+                    };
+                };
+                break;
+
+            
+            case "type:string":
+                doc.add(
+                    new StringField(
+                        mf.key,
+                        mf.values.get(0),
+                        Field.Store.YES
+                        )
+                    );
+                break;
+
+            case "type:keywords":
+                doc.add(
+                    new Field(
+                        mf.key,
+                        String.join(" ", mf.values),
+                        keywordField
+                        )
+                    );
+                break;
+            
+            case "type:text":
+                doc.add(new TextPrependedField(mf.key, mf.values.get(0)));
+                break;
+
+            case "type:attachement":
+            case "type:store":
+                doc.add(new StoredField(mf.key, mf.values.get(0)));
+           	};
+        };
+
+        return doc;
     };
-
-    public void addInt (String key, String value) {
-		if (value != null)
-			this.addInt(key, Integer.parseInt(value));
-    };
-
-    @Override
-    public void addDate (String key, String value) {
-        if (value == null)
-            return;
-
-        KrillDate date = new KrillDate(value);
-		if (date != null) {
-			this.addInt(key, date.toString());
-		};
-        mFields.add(
-            new MetaField(
-                key,
-                "type:date",
-                date.toDisplay()
-                )
-            );
-    }
-
-    @Override
-    public void addText (String key, String value) {
-        if (value == null)
-            return;
-
-        mFields.add(
-            new MetaField(
-                key,
-                "type:text",
-                value
-                )
-            );
-		doc.add(new TextPrependedField(key, value));
-    };
-
-
-    @Override
-    public void addKeywords (String key, String value) {
-        if (value == null)
-            return;
-
-        mFields.add(
-            new MetaField(
-                key,
-                "type:keywords",
-                value
-                )
-            );
-
-        doc.add(new Field(key, value, keywordField));
-    };
-
-    @Override
-    public void addString (String key, String value) {
-        if (value == null)
-            return;
-        
-        mFields.add(
-            new MetaField(
-                key,
-                "type:string",
-                value
-                )
-            );
-        doc.add(new StringField(key, value, Field.Store.YES));
-    };
-
-    public void addAttachement (String key, String value) {
-        if (value == null)
-            return;
-
-        mFields.add(
-            new MetaField(
-                key,
-                "type:attachement",
-                value
-                )
-            );
-        doc.add(new StoredField(key, value));
-    };    
-
-    @Override
-    public void addStored (String key, String value) {
-        if (value == null)
-            return;
-
-        mFields.add(
-            new MetaField(
-                key,
-                "type:store",
-                value
-                )
-            );
-        doc.add(new StoredField(key, value));
-    };
-
-
-    public void addStored (String key, int value) {
-        mFields.add(
-            new MetaField(
-                key,
-                "type:store",
-                new Integer(value).toString()
-                )
-            );
-        doc.add(new StoredField(key, value));
-    };
-
+   
 
     public void addTV (String key, String value, String tsString) {
         this.addTV(key, value, new MultiTermTokenStream(tsString));
@@ -298,6 +249,7 @@
     /**
      * Deserialize koral:field types for meta data
      */
+    // Temporarily this needs to be in a "metaFields" parameter
     public void setMetaFields (ArrayList<Map<String, JsonNode>> fields) {
         String type, key, value;
         StringBuffer sb = new StringBuffer();
diff --git a/src/main/java/de/ids_mannheim/korap/response/MetaFieldsObj.java b/src/main/java/de/ids_mannheim/korap/response/MetaFieldsObj.java
index 82534ba..51131e3 100644
--- a/src/main/java/de/ids_mannheim/korap/response/MetaFieldsObj.java
+++ b/src/main/java/de/ids_mannheim/korap/response/MetaFieldsObj.java
@@ -52,14 +52,12 @@
 	 * Add field to collection
 	 */
 	public MetaField add (IndexableField iField) {
-        MetaField mf = metaFieldFromIndexableField(iField);
-
-		// Ignore non-stored fields
-		if (mf == null)
-			return null;
-
-        fieldsMap.put(mf.key, mf);
-        return mf;
+        return this.add(
+            metaFieldFromIndexableField(
+                iField,
+                new MetaField(iField.name())
+                )
+            );
 	};
 
 
@@ -78,7 +76,7 @@
     
     // Field type needs to be restored heuristically
     // - though that's not very elegant
-    public static MetaField metaFieldFromIndexableField (IndexableField iField) {
+    public static MetaField metaFieldFromIndexableField (IndexableField iField, MetaField mf) {
 		IndexableFieldType iFieldType = iField.fieldType();
 
 		// Field type needs to be restored heuristically
@@ -87,8 +85,6 @@
 		// Ignore non-stored fields
 		if (!iFieldType.stored())
 			return null;
-
-		MetaField mf = new MetaField(iField.name());
 		
 		// TODO: Check if metaField exists for that field
 
diff --git a/src/main/java/de/ids_mannheim/korap/util/KrillDate.java b/src/main/java/de/ids_mannheim/korap/util/KrillDate.java
index a578fdd..3e5f3c1 100644
--- a/src/main/java/de/ids_mannheim/korap/util/KrillDate.java
+++ b/src/main/java/de/ids_mannheim/korap/util/KrillDate.java
@@ -164,6 +164,16 @@
 
 
     /**
+     * Return the date as an integer
+     * based on the stringification.
+     * 
+     * @return The date as an integer.
+     */
+    public int toInteger () throws NumberFormatException {
+        return Integer.parseInt(this.toString());
+    };
+
+    /**
      * Serialize ceiled date to string.
      * 
      * @return The date as a string.
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 faf739c..dcaa5c3 100644
--- a/src/test/java/de/ids_mannheim/korap/index/TestFieldDocument.java
+++ b/src/test/java/de/ids_mannheim/korap/index/TestFieldDocument.java
@@ -27,6 +27,9 @@
 import de.ids_mannheim.korap.response.Result;
 import de.ids_mannheim.korap.util.QueryException;
 
+import org.apache.lucene.document.Document;
+
+
 @RunWith(JUnit4.class)
 public class TestFieldDocument {
 
@@ -48,41 +51,43 @@
                 + "[(1-2)s:b|i:b|_1$<i>1<i>2]" + "[(2-3)s:c|i:c|_2$<i>2<i>3]");
         fd.addAttachement("Wikilink", "data:application/x.korap-link,https://de.wikipedia.org/wiki/Beispiel");
 
-        assertEquals(fd.doc.getField("title").name(), "title");
-        assertEquals(fd.doc.getField("title").stringValue(), "Wikipedia");
+        Document doc = fd.compile();
+        
+        assertEquals(doc.getField("title").name(), "title");
+        assertEquals(doc.getField("title").stringValue(), "Wikipedia");
 
-        assertEquals(fd.doc.getField("corpusID").name(), "corpusID");
-        assertEquals(fd.doc.getField("corpusID").stringValue(), "WPD");
+        assertEquals(doc.getField("corpusID").name(), "corpusID");
+        assertEquals(doc.getField("corpusID").stringValue(), "WPD");
 
-        assertEquals(fd.doc.getField("ID").name(), "ID");
-        assertEquals(fd.doc.getField("ID").stringValue(), "WPD-AAA-00001");
+        assertEquals(doc.getField("ID").name(), "ID");
+        assertEquals(doc.getField("ID").stringValue(), "WPD-AAA-00001");
 
-        assertEquals(fd.doc.getField("subTitle").name(), "subTitle");
-        assertEquals(fd.doc.getField("subTitle").stringValue(),
+        assertEquals(doc.getField("subTitle").name(), "subTitle");
+        assertEquals(doc.getField("subTitle").stringValue(),
                 "Die freie Enzyklopädie");
 
-        assertEquals(fd.doc.getField("pubPlace").name(), "pubPlace");
-        assertEquals(fd.doc.getField("pubPlace").stringValue(), "Bochum");
+        assertEquals(doc.getField("pubPlace").name(), "pubPlace");
+        assertEquals(doc.getField("pubPlace").stringValue(), "Bochum");
 
-        assertEquals(fd.doc.getField("lastModified").name(), "lastModified");
-        assertEquals(fd.doc.getField("lastModified").stringValue(), "20130717");
+        assertEquals(doc.getField("lastModified").name(), "lastModified");
+        assertEquals(doc.getField("lastModified").stringValue(), "20130717");
 
-        assertEquals(fd.doc.getField("tokens").name(), "tokens");
-        assertEquals(fd.doc.getField("tokens").stringValue(), "abc");
+        assertEquals(doc.getField("tokens").name(), "tokens");
+        assertEquals(doc.getField("tokens").stringValue(), "abc");
 
-        assertEquals(fd.doc.getField("author").name(), "author");
-        assertEquals(fd.doc.getField("author").stringValue(),
+        assertEquals(doc.getField("author").name(), "author");
+        assertEquals(doc.getField("author").stringValue(),
                 "Peter Frankenfeld");
 
-        assertEquals(fd.doc.getField("layerInfo").name(), "layerInfo");
-        assertEquals(fd.doc.getField("layerInfo").stringValue(),
+        assertEquals(doc.getField("layerInfo").name(), "layerInfo");
+        assertEquals(doc.getField("layerInfo").stringValue(),
                 "opennlp/p=pos");
 
-        assertEquals(fd.doc.getField("textClass").name(), "textClass");
-        assertEquals(fd.doc.getField("textClass").stringValue(),
+        assertEquals(doc.getField("textClass").name(), "textClass");
+        assertEquals(doc.getField("textClass").stringValue(),
                 "music entertainment");
-        assertEquals(fd.doc.getField("Wikilink").name(), "Wikilink");
-        assertEquals(fd.doc.getField("Wikilink").stringValue(),
+        assertEquals(doc.getField("Wikilink").name(), "Wikilink");
+        assertEquals(doc.getField("Wikilink").stringValue(),
                      "data:application/x.korap-link,https://de.wikipedia.org/wiki/Beispiel"
             );
     };
diff --git a/src/test/java/de/ids_mannheim/korap/index/TestKrillIndex.java b/src/test/java/de/ids_mannheim/korap/index/TestKrillIndex.java
index 8518f90..934ac83 100644
--- a/src/test/java/de/ids_mannheim/korap/index/TestKrillIndex.java
+++ b/src/test/java/de/ids_mannheim/korap/index/TestKrillIndex.java
@@ -198,11 +198,12 @@
 		fd.addStored("ref", "My reference");
 		fd.addAttachement("ref2", "data:text/plain;charset=UTF-8,My reference2");
 
-/*
+        /*
 		fd.addKeywords("keyword", "baum");
 		fd.addKeywords("keyword", "wald");
-*/
-		fd.addKeywords("keyword", "baum wald");
+        */
+
+        fd.addKeywords("keyword", "baum wald");
 
 		fd.addText("title", "Der Name der Rose");