diff --git a/ng2-components/ng2-activiti-processlist/src/components/activiti-process-instance-tasks.component.html b/ng2-components/ng2-activiti-processlist/src/components/activiti-process-instance-tasks.component.html
index 905eedecbb..6479728a12 100644
--- a/ng2-components/ng2-activiti-processlist/src/components/activiti-process-instance-tasks.component.html
+++ b/ng2-components/ng2-activiti-processlist/src/components/activiti-process-instance-tasks.component.html
@@ -81,7 +81,7 @@
 <dialog class="mdl-dialog task-details-dialog" #startDialog>
     <h4 class="mdl-dialog__title">{{ 'DETAILS.LABELS.START_FORM'|translate }}</h4>
     <div class="mdl-dialog__content">
-        <activiti-start-form [processId]="processId" [processDefinitionId]="processInstanceDetails.processDefinitionId"
+        <activiti-start-form [processId]="processId" [processDefinitionId]="processInstanceDetails?.processDefinitionId"
                              [showOutcomeButtons]="false" [showRefreshButton]="false">
         </activiti-start-form>
     </div>