diff --git a/src/aks-preview/azext_aks_preview/custom.py b/src/aks-preview/azext_aks_preview/custom.py
index 6f4f35c18b5..42060b57fb6 100644
--- a/src/aks-preview/azext_aks_preview/custom.py
+++ b/src/aks-preview/azext_aks_preview/custom.py
@@ -492,7 +492,7 @@ def aks_create(
     disable_public_fqdn=False,
     service_principal=None,
     client_secret=None,
-    enable_managed_identity=False,
+    enable_managed_identity=None,
     assign_identity=None,
     assign_kubelet_identity=None,
     enable_aad=False,
diff --git a/src/aks-preview/azext_aks_preview/tests/latest/test_managed_cluster_decorator.py b/src/aks-preview/azext_aks_preview/tests/latest/test_managed_cluster_decorator.py
index 00b84d67193..324e419390b 100644
--- a/src/aks-preview/azext_aks_preview/tests/latest/test_managed_cluster_decorator.py
+++ b/src/aks-preview/azext_aks_preview/tests/latest/test_managed_cluster_decorator.py
@@ -1103,6 +1103,37 @@ def test_get_enable_managed_identity(self):
         with self.assertRaises(RequiredArgumentMissingError):
             self.assertEqual(ctx_2.get_enable_managed_identity(), False)
 
+        # custom value
+        ctx_3 = AKSPreviewManagedClusterContext(
+            self.cmd,
+            AKSManagedClusterParamDict(
+                {
+                    "enable_managed_identity": None,
+                }
+            ),
+            self.models,
+            DecoratorMode.CREATE,
+        )
+        self.assertEqual(ctx_3.get_enable_managed_identity(), True)
+
+        # custom value
+        ctx_4 = AKSPreviewManagedClusterContext(
+            self.cmd,
+            AKSManagedClusterParamDict(
+                {
+                    "enable_managed_identity": False,
+                }
+            ),
+            self.models,
+            DecoratorMode.UPDATE,
+        )
+        self.assertEqual(ctx_4.get_enable_managed_identity(), False)
+        mc_4 = self.models.ManagedCluster(location="test_location", identity=self.models.ManagedClusterIdentity(
+            type="SystemAssigned"
+        ))
+        ctx_4.attach_mc(mc_4)
+        self.assertEqual(ctx_4.get_enable_managed_identity(), False)
+
     def test_get_enable_pod_identity(self):
         # default
         ctx_1 = AKSPreviewManagedClusterContext(