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 f672f08..75e55ee 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
@@ -100,7 +100,7 @@
         return meta;
     }
 
-    public class SpanContext {
+    public static class SpanContext {
         private String left_type;
         private String right_type;
         private int left_size;