diff --git a/lib/features/modeling/cmd/UpdateFlowNodeRefsHandler.js b/lib/features/modeling/cmd/UpdateFlowNodeRefsHandler.js
index a1a0bfbe..efd30d0e 100644
--- a/lib/features/modeling/cmd/UpdateFlowNodeRefsHandler.js
+++ b/lib/features/modeling/cmd/UpdateFlowNodeRefsHandler.js
@@ -34,7 +34,7 @@ UpdateFlowNodeRefsHandler.$inject = [
 
 UpdateFlowNodeRefsHandler.prototype.computeUpdates = function(flowNodeShapes, laneShapes) {
 
-  var handledNodes = {};
+  var handledNodes = [];
 
   var updates = [];
 
@@ -58,9 +58,9 @@ UpdateFlowNodeRefsHandler.prototype.computeUpdates = function(flowNodeShapes, la
   }
 
   function addFlowNodeShape(flowNodeShape) {
-    if (!handledNodes[flowNodeShape.id]) {
+    if (handledNodes.indexOf(flowNodeShape) === -1) {
       allFlowNodeShapes.push(flowNodeShape);
-      handledNodes[flowNodeShape.id] = flowNodeShape;
+      handledNodes.push(flowNodeShape);
     }
   }
 
@@ -92,7 +92,7 @@ UpdateFlowNodeRefsHandler.prototype.computeUpdates = function(flowNodeShapes, la
   laneShapes.forEach(function(laneShape) {
     var root = getLanesRoot(laneShape);
 
-    if (!root || handledNodes[root.id]) {
+    if (!root || handledNodes.indexOf(root) !== -1) {
       return;
     }
 
@@ -102,7 +102,7 @@ UpdateFlowNodeRefsHandler.prototype.computeUpdates = function(flowNodeShapes, la
 
     children.forEach(addFlowNodeShape);
 
-    handledNodes[root.id] = root;
+    handledNodes.push(root);
   });
 
   flowNodeShapes.forEach(addFlowNodeShape);
@@ -190,4 +190,4 @@ UpdateFlowNodeRefsHandler.prototype.revert = function(context) {
 
   // TODO(nikku): return changed elements
   // return [ ... ];
-};
\ No newline at end of file
+};
diff --git a/test/spec/features/modeling/lanes/UpdateFlowNodeRefsSpec.js b/test/spec/features/modeling/lanes/UpdateFlowNodeRefsSpec.js
index d969e4cf..3b32b9f9 100644
--- a/test/spec/features/modeling/lanes/UpdateFlowNodeRefsSpec.js
+++ b/test/spec/features/modeling/lanes/UpdateFlowNodeRefsSpec.js
@@ -266,4 +266,28 @@ describe('features/modeling - lanes - flowNodeRefs', function() {
     expect(sourceLane.flowNodeRef).not.to.contain(event);
   }));
 
+
+  it('should not create duplicate refs on attaching / detaching', inject(function(elementRegistry, modeling) {
+
+    // given
+    var eventID = 'IntermediateThrowEvent',
+        throwEvent = elementRegistry.get(eventID),
+        task1 = elementRegistry.get('Task_1'),
+        task2 = elementRegistry.get('Task_2'),
+        lane1 = elementRegistry.get('Participant_C_Lane_1').businessObject,
+        lane2 = elementRegistry.get('Participant_C_Lane_2').businessObject;
+
+    // when
+    modeling.moveElements([ throwEvent ], { x: -280, y: 30 }, task1, { attach: true });
+
+    var boundaryEvent = elementRegistry.get(eventID);
+
+    modeling.moveElements([ boundaryEvent ], { x: 0, y: 150 }, task2, { attach: true });
+
+    // then
+    expect(lane1.flowNodeRef).not.to.contain(boundaryEvent.businessObject);
+    expect(lane2.flowNodeRef).to.contain(boundaryEvent.businessObject);
+    expect(lane1.flowNodeRef).to.have.length(1);
+    expect(lane2.flowNodeRef).to.have.length(2);
+  }));
 });
diff --git a/test/spec/features/modeling/lanes/flowNodeRefs.bpmn b/test/spec/features/modeling/lanes/flowNodeRefs.bpmn
index dfa65134..3a405db1 100644
--- a/test/spec/features/modeling/lanes/flowNodeRefs.bpmn
+++ b/test/spec/features/modeling/lanes/flowNodeRefs.bpmn
@@ -1,8 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<bpmn2:definitions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:bpmn2="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" xsi:schemaLocation="http://www.omg.org/spec/BPMN/20100524/MODEL BPMN20.xsd" id="_2_FUoE-xEeWT0c1N_GlSWA" exporter="camunda modeler" exporterVersion="2.6.0" targetNamespace="http://activiti.org/bpmn">
+<bpmn2:definitions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:bpmn2="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" id="_2_FUoE-xEeWT0c1N_GlSWA" targetNamespace="http://activiti.org/bpmn" exporter="Camunda Modeler" exporterVersion="3.4.0-dev" xsi:schemaLocation="http://www.omg.org/spec/BPMN/20100524/MODEL BPMN20.xsd">
   <bpmn2:collaboration id="_Collaboration_2">
-    <bpmn2:participant id="Participant_A" name="Participant_A" processRef="Process_A"/>
-    <bpmn2:participant id="Participant_B" name="Participant_B" processRef="Process_B"/>
+    <bpmn2:participant id="Participant_A" name="Participant_A" processRef="Process_A" />
+    <bpmn2:participant id="Participant_B" name="Participant_B" processRef="Process_B" />
+    <bpmn2:participant id="Participant_0emukbw" name="Participant_C" processRef="Process_1gjk6nk" />
   </bpmn2:collaboration>
   <bpmn2:process id="Process_A" isExecutable="false">
     <bpmn2:laneSet id="LaneSet_1" name="Lane Set 1">
@@ -14,44 +15,76 @@
     <bpmn2:task id="Task_A" name="Task_A">
       <bpmn2:outgoing>SequenceFlow</bpmn2:outgoing>
     </bpmn2:task>
-    <bpmn2:sequenceFlow id="SequenceFlow" name="" sourceRef="Task_A" targetRef="Event"/>
     <bpmn2:intermediateCatchEvent id="Event" name="Event">
       <bpmn2:incoming>SequenceFlow</bpmn2:incoming>
     </bpmn2:intermediateCatchEvent>
+    <bpmn2:sequenceFlow id="SequenceFlow" name="" sourceRef="Task_A" targetRef="Event" />
   </bpmn2:process>
   <bpmn2:process id="Process_B" isExecutable="false">
-    <bpmn2:task id="Task_B" name="Task_B"/>
+    <bpmn2:task id="Task_B" name="Task_B" />
+  </bpmn2:process>
+  <bpmn2:process id="Process_1gjk6nk" isExecutable="false">
+    <bpmn2:laneSet id="LaneSet_06y7y48">
+      <bpmn2:lane id="Participant_C_Lane_1">
+        <bpmn2:flowNodeRef>Task_1</bpmn2:flowNodeRef>
+        <bpmn2:flowNodeRef>IntermediateThrowEvent</bpmn2:flowNodeRef>
+      </bpmn2:lane>
+      <bpmn2:lane id="Participant_C_Lane_2">
+        <bpmn2:flowNodeRef>Task_2</bpmn2:flowNodeRef>
+      </bpmn2:lane>
+    </bpmn2:laneSet>
+    <bpmn2:task id="Task_1" />
+    <bpmn2:task id="Task_2" />
+    <bpmn2:intermediateThrowEvent id="IntermediateThrowEvent" />
   </bpmn2:process>
   <bpmndi:BPMNDiagram id="BPMNDiagram_1">
     <bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="_Collaboration_2">
       <bpmndi:BPMNShape id="_BPMNShape_Participant_2" bpmnElement="Participant_A" isHorizontal="true">
-        <dc:Bounds height="145.0" width="540.0" x="84.0" y="96.0"/>
+        <dc:Bounds x="154" y="96" width="540" height="145" />
       </bpmndi:BPMNShape>
       <bpmndi:BPMNShape id="_BPMNShape_Participant_3" bpmnElement="Participant_B" isHorizontal="true">
-        <dc:Bounds height="133.0" width="540.0" x="84.0" y="312.0"/>
+        <dc:Bounds x="154" y="312" width="540" height="133" />
       </bpmndi:BPMNShape>
       <bpmndi:BPMNShape id="_BPMNShape_Task_2" bpmnElement="Task_A">
-        <dc:Bounds height="80.0" width="100.0" x="168.0" y="129.0"/>
+        <dc:Bounds x="238" y="129" width="100" height="80" />
       </bpmndi:BPMNShape>
       <bpmndi:BPMNShape id="_BPMNShape_Lane_2" bpmnElement="Lane" isHorizontal="true">
-        <dc:Bounds height="145.0" width="510.0" x="114.0" y="96.0"/>
+        <dc:Bounds x="184" y="96" width="510" height="145" />
       </bpmndi:BPMNShape>
       <bpmndi:BPMNShape id="_BPMNShape_IntermediateCatchEvent_2" bpmnElement="Event">
-        <dc:Bounds height="36.0" width="36.0" x="384.0" y="151.0"/>
+        <dc:Bounds x="454" y="151" width="36" height="36" />
         <bpmndi:BPMNLabel>
-          <dc:Bounds height="21.0" width="112.0" x="346.0" y="192.0"/>
+          <dc:Bounds x="458" y="192" width="29" height="14" />
         </bpmndi:BPMNLabel>
       </bpmndi:BPMNShape>
       <bpmndi:BPMNEdge id="BPMNEdge_SequenceFlow_1" bpmnElement="SequenceFlow" sourceElement="_BPMNShape_Task_2" targetElement="_BPMNShape_IntermediateCatchEvent_2">
-        <di:waypoint xsi:type="dc:Point" x="268.0" y="169.0"/>
-        <di:waypoint xsi:type="dc:Point" x="384.0" y="169.0"/>
+        <di:waypoint x="338" y="169" />
+        <di:waypoint x="454" y="169" />
         <bpmndi:BPMNLabel>
-          <dc:Bounds height="6.0" width="6.0" x="290.0" y="169.0"/>
+          <dc:Bounds x="290" y="169" width="6" height="6" />
         </bpmndi:BPMNLabel>
       </bpmndi:BPMNEdge>
       <bpmndi:BPMNShape id="_BPMNShape_Task_3" bpmnElement="Task_B">
-        <dc:Bounds height="80.0" width="100.0" x="492.0" y="339.0"/>
+        <dc:Bounds x="562" y="339" width="100" height="80" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Participant_0emukbw_di" bpmnElement="Participant_0emukbw" isHorizontal="true">
+        <dc:Bounds x="154" y="475" width="540" height="285" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Lane_0lsm3hs_di" bpmnElement="Participant_C_Lane_1" isHorizontal="true">
+        <dc:Bounds x="184" y="475" width="510" height="150" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Lane_16dmnot_di" bpmnElement="Participant_C_Lane_2" isHorizontal="true">
+        <dc:Bounds x="184" y="625" width="510" height="135" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Task_1abs8bh_di" bpmnElement="Task_1">
+        <dc:Bounds x="230" y="510" width="100" height="80" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="IntermediateThrowEvent_0oto7vx_di" bpmnElement="IntermediateThrowEvent">
+        <dc:Bounds x="592" y="532" width="36" height="36" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Task_0j7a294_di" bpmnElement="Task_2">
+        <dc:Bounds x="230" y="650" width="100" height="80" />
       </bpmndi:BPMNShape>
     </bpmndi:BPMNPlane>
   </bpmndi:BPMNDiagram>
-</bpmn2:definitions>
\ No newline at end of file
+</bpmn2:definitions>