diff --git a/pom.xml b/pom.xml
index 042468d..2f9e9d5 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
   <groupId>de.ids_mannheim.korap</groupId>
   <artifactId>Koral</artifactId>
-  <version>0.2</version>
+  <version>0.21</version>
   <packaging>jar</packaging>
   <name>Koral</name>
   <url>http://maven.apache.org</url>
diff --git a/src/main/java/de/ids_mannheim/korap/query/serialize/MetaQueryBuilder.java b/src/main/java/de/ids_mannheim/korap/query/serialize/MetaQueryBuilder.java
index 22963a5..f743aba 100644
--- a/src/main/java/de/ids_mannheim/korap/query/serialize/MetaQueryBuilder.java
+++ b/src/main/java/de/ids_mannheim/korap/query/serialize/MetaQueryBuilder.java
@@ -6,6 +6,7 @@
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.regex.Pattern;
 
 /**
  * @author hanl
@@ -13,12 +14,14 @@
  */
 public class MetaQueryBuilder {
 
+    private static Pattern p = Pattern
+            .compile("\\s*\\d+-(?:c(?:hars?)?|t(?:okens?)?)");
     private Map meta;
     private SpanContext spanContext;
 
     public MetaQueryBuilder() {
         this.meta = new LinkedHashMap();
-        this.meta.put("fields", new LinkedList<>());
+        //        this.meta.put("fields", new LinkedList<>());
     }
 
     /**
@@ -52,7 +55,7 @@
      */
     public MetaQueryBuilder setSpanContext(String context) {
         if (context != null) {
-            if (!context.contains("-") || context.contains(":"))
+            if (!p.matcher(context).find())
                 this.spanContext = new SpanContext(context);
             else {
                 String[] ct = context.replaceAll("\\s+", "").split(",");
@@ -77,8 +80,6 @@
         return meta;
     }
 
-
-
     @Data
     public class SpanContext {
         private String left_type;