diff --git a/src/test/java/de/ids_mannheim/korap/query/TestSpanSequenceQueryJSON.java b/src/test/java/de/ids_mannheim/korap/query/TestSpanSequenceQueryJSON.java
index 62b5f7e..d0e952c 100644
--- a/src/test/java/de/ids_mannheim/korap/query/TestSpanSequenceQueryJSON.java
+++ b/src/test/java/de/ids_mannheim/korap/query/TestSpanSequenceQueryJSON.java
@@ -411,6 +411,16 @@
 					 "(base/s:s[0:0], ordered, notExcluded)])");
     };
 
+
+	@Test
+    public void queryJSONdistanceMultipleOps () throws QueryException {
+
+        SpanQueryWrapper sqwi = getJsonQuery(getClass().getResource("/queries/sequence/distance-with-multiple-ops.jsonld").getFile());
+        SpanQuery sq = sqwi.toQuery();
+        assertEquals(sq.toString(),"spanDistance(spanDistance(tokens:s:der, tokens:s:alte, [(w[2:2], ordered, notExcluded)]), tokens:s:Baum, [(w[2:2], ordered, notExcluded)])");
+    };
+
+    
 	@Test
     public void queryJSONcosmas2Bug2 () throws QueryException {
 
diff --git a/src/test/resources/queries/reference/bug-class-in-reference.jsonld b/src/test/resources/queries/reference/bug-class-in-reference.jsonld
new file mode 100644
index 0000000..a7d58e7
--- /dev/null
+++ b/src/test/resources/queries/reference/bug-class-in-reference.jsonld
@@ -0,0 +1,70 @@
+{
+  "query":{
+    "operands":[
+      {
+        "operands":[
+          {
+            "operands":[
+              {
+                "operands":[
+                  {
+                    "@type":"koral:token",
+                    "wrap":{
+                      "@type":"koral:term",
+                      "match":"match:eq",
+                      "layer":"orth",
+                      "key":"ich"
+                    }
+                  }
+                ],
+                "classOut":129,
+                "@type":"koral:group",
+                "operation":"operation:class"
+              },
+              {
+                "operands":[
+                  {
+                    "@type":"koral:token",
+                    "wrap":{
+                      "@type":"koral:term",
+                      "match":"match:eq",
+                      "layer":"p",
+                      "key":"VVFIN"
+                    }
+                  }
+                ],
+                "classOut":130,
+                "@type":"koral:group",
+                "operation":"operation:class"
+              }
+            ],
+            "@type":"koral:group",
+            "relType":{
+              "@type":"koral:relation",
+              "wrap":{
+                "foundry":"malt",
+                "@type":"koral:term",
+                "match":"match:eq",
+                "layer":"d",
+                "key":"SUBJ"
+              }
+            },
+            "operation":"operation:relation"
+          }
+        ],
+        "@type":"koral:reference",
+        "operation":"operation:focus",
+        "classRef":[129]
+      },
+      {
+        "@type":"koral:reference",
+        "operation":"operation:focus",
+        "classRef":[130]
+      }
+    ],
+    "@type":"koral:group",
+    "inOrder":true,
+    "operation":"operation:sequence"
+  },
+  "@context":"http://korap.ids-mannheim.de/ns/koral/0.3/context.jsonld"
+}
diff --git a/src/test/resources/queries/sequence/distance-with-multiple-ops.jsonld b/src/test/resources/queries/sequence/distance-with-multiple-ops.jsonld
new file mode 100644
index 0000000..224711b
--- /dev/null
+++ b/src/test/resources/queries/sequence/distance-with-multiple-ops.jsonld
@@ -0,0 +1,48 @@
+{
+  "@context": "http://korap.ids-mannheim.de/ns/KoralQuery/v0.3/context.jsonld",
+  "query": {
+    "inOrder": true,
+    "operands": [
+      {
+        "@type": "koral:token",
+        "wrap": {
+          "match": "match:eq",
+          "layer": "orth",
+          "key": "der",
+          "@type": "koral:term"
+        }
+      },
+      {
+        "@type": "koral:token",
+        "wrap": {
+          "match": "match:eq",
+          "layer": "orth",
+          "key": "alte",
+          "@type": "koral:term"
+        }
+      },
+      {
+        "wrap": {
+          "match": "match:eq",
+          "layer": "orth",
+          "key": "Baum",
+          "@type": "koral:term"
+        },
+        "@type": "koral:token"
+      }
+    ],
+    "operation": "operation:sequence",
+    "distances": [
+      {
+        "key": "w",
+        "@type": "koral:distance",
+        "boundary": {
+          "@type": "koral:boundary",
+          "max": 1,
+          "min": 1
+        }
+      }
+    ],
+    "@type": "koral:group"
+  }
+}