diff --git a/src/main/java/de/ids_mannheim/korap/query/serialize/PoliqarpPlusTree.java b/src/main/java/de/ids_mannheim/korap/query/serialize/PoliqarpPlusTree.java
index 397ee5f..f97bd4e 100644
--- a/src/main/java/de/ids_mannheim/korap/query/serialize/PoliqarpPlusTree.java
+++ b/src/main/java/de/ids_mannheim/korap/query/serialize/PoliqarpPlusTree.java
@@ -137,8 +137,7 @@
 		}
 
 		if (nodeCat.equals("emptyTokenSequenceClass")) {
-			Integer[] minmax = parseDistance(node);
-			int classId = 0;
+			int classId = 1;
 			if (hasChild(node, "spanclass_id")) {
 				classId = Integer.parseInt(node.getChild(1).getChild(0).toStringTree(parser));
 			}
diff --git a/src/test/java/PoliqarpPlusTreeTest.java b/src/test/java/PoliqarpPlusTreeTest.java
index 8042aa5..07df5c3 100644
--- a/src/test/java/PoliqarpPlusTreeTest.java
+++ b/src/test/java/PoliqarpPlusTreeTest.java
@@ -452,6 +452,18 @@
 		map = ppt.getRequestMap().get("query").toString();
 		assertEquals(expected.replaceAll(" ", ""), map.replaceAll(" ", ""));
 		
+		query = "{[]}[base=Mann]";
+		expected = 
+				"{@type=korap:group, operation=operation:sequence, operands=[" +
+					"{@type=korap:group, operation=operation:class, class=1, classOut=1, operands=[" +
+						"{@type=korap:token}" +
+					"]}," +
+					"{@type=korap:token, wrap={@type=korap:term, layer=lemma, key=Mann, match=match:eq}}" +
+				"]}";
+		ppt = new PoliqarpPlusTree(query);
+		map = ppt.getRequestMap().get("query").toString();
+		assertEquals(expected.replaceAll(" ", ""), map.replaceAll(" ", ""));
+		
 		query = "[][][base=Mann]";
 		expected = 
 				"{@type=korap:group, operation=operation:sequence, operands=[" +