diff --git a/Schemas/Collaboration/Topic/topic_GET.json b/Schemas/Collaboration/Topic/topic_GET.json
index 34e30e0..7ee7fd7 100644
--- a/Schemas/Collaboration/Topic/topic_GET.json
+++ b/Schemas/Collaboration/Topic/topic_GET.json
@@ -80,6 +80,9 @@
                 "$ref": "../RelatedTopic/related_topic_GET.json"
             }
         },
+        "main_viewpoint_guid": {
+            "type": ["string", "null"]
+        },
         "authorization": {
             "type": "object",
             "required": false,
diff --git a/Schemas/Collaboration/Topic/topic_POST.json b/Schemas/Collaboration/Topic/topic_POST.json
index adafe8d..cb0e5a6 100644
--- a/Schemas/Collaboration/Topic/topic_POST.json
+++ b/Schemas/Collaboration/Topic/topic_POST.json
@@ -57,6 +57,9 @@
         },
         "custom_fields": {
             "$ref": "custom_fields.json"
+        },
+        "main_viewpoint_guid": {
+            "type": ["string", "null"]
         }
     }
 }
diff --git a/Schemas/Collaboration/Topic/topic_PUT.json b/Schemas/Collaboration/Topic/topic_PUT.json
index d024127..125d2a7 100644
--- a/Schemas/Collaboration/Topic/topic_PUT.json
+++ b/Schemas/Collaboration/Topic/topic_PUT.json
@@ -53,6 +53,9 @@
         },
         "custom_fields": {
             "$ref": "custom_fields.json"
+        },
+        "main_viewpoint_guid": {
+            "type": ["string", "null"]
         }
     }
 }