diff --git a/libcove/lib/common.py b/libcove/lib/common.py
index 2bea99f..a3880dd 100644
--- a/libcove/lib/common.py
+++ b/libcove/lib/common.py
@@ -17,6 +17,7 @@
 from flattentool import unflatten
 from flattentool.schema import get_property_type_set
 from jsonschema import FormatChecker, RefResolver
+from jsonschema._utils import uniq
 from jsonschema.exceptions import ValidationError
 
 from .exceptions import cove_spreadsheet_conversion_error
@@ -66,6 +67,7 @@ def unique_ids(validator, ui, instance, schema):
     if ui and validator.is_type(instance, "array"):
         non_unique_ids = set()
         all_ids = set()
+        previous_items = set()
         for item in instance:
             try:
                 item_id = item.get(id_name)
@@ -81,11 +83,12 @@ def unique_ids(validator, ui, instance, schema):
                     non_unique_ids.add(item_id)
                 all_ids.add(item_id)
             else:
-                msg = "Array has non-unique elements"
-                err = ValidationError(msg, instance=instance)
-                err.error_id = "uniqueItems_no_ids"
-                yield err
-                return
+                if uniq(instance):
+                    msg = "Array has non-unique elements"
+                    err = ValidationError(msg, instance=instance)
+                    err.error_id = "uniqueItems_no_ids"
+                    yield err
+                    return
 
         for non_unique_id in sorted(non_unique_ids):
             msg = "Non-unique {} values".format(id_name)
diff --git a/tests/lib/test_common.py b/tests/lib/test_common.py
index 7c44de0..5c3905b 100644
--- a/tests/lib/test_common.py
+++ b/tests/lib/test_common.py
@@ -620,19 +620,6 @@ def get_release_pkg_schema_obj(self):
                     "error_id": None,
                     "values": [{"path": "releases/1"}],
                 },
-                {
-                    "message": "Array has non-unique elements",
-                    "message_safe": "Array has non-unique elements",
-                    "validator": "uniqueItems",
-                    "assumption": None,
-                    "message_type": "uniqueItems",
-                    "path_no_number": "releases",
-                    "header": "releases",
-                    "header_extra": "releases",
-                    "null_clause": "",
-                    "error_id": "uniqueItems_no_ids",
-                    "values": [{"path": "releases"}],
-                },
             ],
         ),
         (
@@ -665,19 +652,6 @@ def get_release_pkg_schema_obj(self):
                     "error_id": None,
                     "values": [{"path": "records/1"}],
                 },
-                {
-                    "message": "Array has non-unique elements",
-                    "message_safe": "Array has non-unique elements",
-                    "validator": "uniqueItems",
-                    "assumption": None,
-                    "message_type": "uniqueItems",
-                    "path_no_number": "records",
-                    "header": "records",
-                    "header_extra": "records",
-                    "null_clause": "",
-                    "error_id": "uniqueItems_no_ids",
-                    "values": [{"path": "records"}],
-                },
             ],
         ),
     ],