diff --git a/package.json b/package.json
index 5048aef2..3a8c21bd 100644
--- a/package.json
+++ b/package.json
@@ -7,7 +7,7 @@
     "dynamo",
     "nosql"
   ],
-  "version": "0.5.21",
+  "version": "0.5.22",
   "files": [
     "lib",
     "LICENSE",
diff --git a/src/mutation/updateItem.ts b/src/mutation/updateItem.ts
index 664bd2b7..547637ce 100644
--- a/src/mutation/updateItem.ts
+++ b/src/mutation/updateItem.ts
@@ -38,6 +38,8 @@ const buildConditionExpressions = (
         expression += `${expressionName} ${operator} :val${i}_1 AND :val${i}_2`;
         attrValues[`:val${i}_1`] = value[0];
         attrValues[`:val${i}_2`] = value[1];
+      } else if (operator === 'ATTRIBUTE_EXISTS' || operator === 'ATTRIBUTE_NOT_EXISTS') {
+        expression += `${operator.toLowerCase()}(${expressionName})`;
       } else {
         expression += `${expressionName} ${operator} :val${i}`;
         attrValues[`:val${i}`] = value;
diff --git a/src/query/queryBuilder.ts b/src/query/queryBuilder.ts
index 4ca09488..5751045f 100644
--- a/src/query/queryBuilder.ts
+++ b/src/query/queryBuilder.ts
@@ -39,6 +39,10 @@ export function keyOperatorLookup(
       return 'BEGINS_WITH';
     case 'exists':
       return 'EXISTS';
+    case 'attribute_exists':
+      return 'ATTRIBUTE_EXISTS';
+    case 'attribute_not_exists':
+      return 'ATTRIBUTE_NOT_EXISTS';
     default:
       return '=';
   }
diff --git a/src/test.ts b/src/test.ts
new file mode 100644
index 00000000..6146fa67
--- /dev/null
+++ b/src/test.ts
@@ -0,0 +1,81 @@
+import { DynamoHelper } from './DynamoHelper';
+import { ConditionExpressionKind, FilterOperators } from './types';
+
+const table = {
+  name: 'till-x-test-in',
+  indexes: {
+    default: {
+      partitionKeyName: 'pk',
+      sortKeyName: 'sk',
+    },
+    gsi1: {
+      partitionKeyName: 'gs1pk',
+      sortKeyName: 'gs1sk',
+    },
+    gsi2: {
+      partitionKeyName: 'gs2pk',
+      sortKeyName: 'gs2sk',
+    },
+    gsi3: {
+      partitionKeyName: 'gs3pk',
+      sortKeyName: 'gs3sk',
+    },
+    gsi4: {
+      partitionKeyName: 'gs4pk',
+      sortKeyName: 'gs4sk',
+    },
+    gsi5: {
+      partitionKeyName: 'gs5pk',
+      sortKeyName: 'gs5sk',
+    },
+    gsi6: {
+      partitionKeyName: 'gs6pk',
+      sortKeyName: 'gs6sk',
+    },
+  },
+};
+const client = new DynamoHelper(table, 'ap-southeast-1');
+
+client
+  .query({
+    where: {
+      pk: 'store#37059ae2-dfb9-40c8-953a-f68aa872c86a#settings',
+      appVersion: { exists: false },
+    },
+  })
+  .then(x => console.log(x, '\n len: ' + x.length));
+
+client
+  .query(
+    {
+      where: {
+        gs1pk: 'deviceprofile#d0c622d0-4343-4583-9c02-54b1865cf609',
+        appVersion: { exists: true },
+      },
+    },
+    'gsi1',
+  )
+  .then(x => console.log(x, '\n len: ' + x.length));
+
+async function testConditionalUpdateItem() {
+  const storeId = '61da543d-1252-45b9-bc98-389c40d96761';
+  const updatedOrder = {
+    pk: `STORE#${storeId}`,
+    sk: 'open-shift',
+    status: 'open',
+    updatedAt: new Date().toISOString(),
+  };
+  await client.updateItem(
+    { pk: updatedOrder.pk, sk: updatedOrder.sk }, // Key object with both partition and sort key
+    updatedOrder,
+    [
+      {
+        kind: ConditionExpressionKind.Comparison,
+        key: 'pk',
+        comparator: ('attribute_not_exists' as unknown) as FilterOperators,
+        value: updatedOrder.pk,
+      },
+    ],
+  );
+}
+testConditionalUpdateItem();
diff --git a/src/types.ts b/src/types.ts
index 3b47cccd..8d3e25fc 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -25,7 +25,9 @@ export type DynamoDBOperators =
   | 'BEGINS_WITH'
   | 'IN'
   | 'EXISTS'
-  | 'CONTAINS';
+  | 'CONTAINS'
+  | 'ATTRIBUTE_EXISTS'
+  | 'ATTRIBUTE_NOT_EXISTS';
 
 /**
  * Operators for where clauses
@@ -41,6 +43,8 @@ export type FilterOperators =
   | 'between'
   | 'like'
   | 'exists'
+  | 'attribute_exists'
+  | 'attribute_not_exists'
   | 'beginsWith';
 /**
  * Matching predicate comparison