diff --git a/CHANGES.rst b/CHANGES.rst
index b29b25bf42..70a01c6db1 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -21,7 +21,8 @@ Changelog
 
 
 **Fixed**
- 
+
+- #813 Saving AR results gives TypeError: can only compare to a set
 - #799 On AR Listing, inline edit for Date Sampled not working when Sampler has a value
 - #776 Analyses submission in Worksheet is slow
 - #726 404 Error raised when clicking Print Samples Sheets from within a client
diff --git a/bika/lims/browser/analyses/workflow.py b/bika/lims/browser/analyses/workflow.py
index 11d2e6271b..70d970d1fd 100644
--- a/bika/lims/browser/analyses/workflow.py
+++ b/bika/lims/browser/analyses/workflow.py
@@ -215,7 +215,7 @@ def workflow_action_submit(self):
         # AR Catalog contains some metadata that that rely on the Analyses an
         # Analysis Request contains.
         if affected_ars:
-            query = dict(UID=affected_ars, portal_type="AnalysisRequest")
+            query = dict(UID=list(affected_ars), portal_type="AnalysisRequest")
             for ar_brain in api.search(query, CATALOG_ANALYSIS_REQUEST_LISTING):
                 if ar_brain.review_state == 'to_be_verified':
                     continue
@@ -226,7 +226,7 @@ def workflow_action_submit(self):
                     ar.reindexObject()
 
         if affected_ws:
-            query = dict(UID=affected_ws, portal_type="Worksheet")
+            query = dict(UID=list(affected_ws), portal_type="Worksheet")
             for ws_brain in api.search(query, CATALOG_WORKSHEET_LISTING):
                 if ws_brain.review_state == 'to_be_verified':
                     continue