diff --git a/packages/orm/src/client/crud/operations/base.ts b/packages/orm/src/client/crud/operations/base.ts
index d696f82ff..0314bcf95 100644
--- a/packages/orm/src/client/crud/operations/base.ts
+++ b/packages/orm/src/client/crud/operations/base.ts
@@ -1228,8 +1228,10 @@ export abstract class BaseOperationHandler<Schema extends SchemaDef> {
             );
             // only fields not consumed by base update will be used for this model
             finalData = baseUpdateResult.remainingFields;
-            // base update may change entity ids, update the filter
-            combinedWhere = baseUpdateResult.baseEntity;
+            // make sure to include only the id fields from the base entity in the final filter
+            combinedWhere = baseUpdateResult.baseEntity
+                ? getIdValues(this.schema, modelDef.baseModel!, baseUpdateResult.baseEntity)
+                : baseUpdateResult.baseEntity;
 
             // update this entity with fields in updated base
             if (baseUpdateResult.baseEntity) {
diff --git a/tests/e2e/orm/plugin-infra/entity-mutation-hooks.test.ts b/tests/e2e/orm/plugin-infra/entity-mutation-hooks.test.ts
index eb8a25f16..ceb063fe8 100644
--- a/tests/e2e/orm/plugin-infra/entity-mutation-hooks.test.ts
+++ b/tests/e2e/orm/plugin-infra/entity-mutation-hooks.test.ts
@@ -692,3 +692,45 @@ describe('Entity mutation hooks tests', () => {
         });
     });
 });
+
+describe('Entity mutation hooks - delegate model interaction', () => {
+    it('update on child model succeeds with afterEntityMutation plugin', async () => {
+        console.log('RUNNING!!!!');
+        const client = await createTestClient(
+            `
+model Base {
+    id Int @id @default(autoincrement())
+    orgId Int
+    type String
+    @@delegate(type)
+}
+
+model Child extends Base {
+    childField Int
+}
+`,
+        );
+
+        const withPlugin = client.$use({
+            id: 'test',
+            onEntityMutation: {
+                afterEntityMutation() {},
+            },
+        });
+
+        const created = await withPlugin.child.create({
+            data: { orgId: 1, childField: 10 },
+        });
+
+        const updated = await withPlugin.child.update({
+            where: { id: created.id },
+            data: { orgId: 2, childField: 20 },
+        });
+
+        expect(updated).toBeTruthy();
+        expect(updated.orgId).toBe(2);
+        expect(updated.childField).toBe(20);
+
+        await client.$disconnect();
+    });
+});