diff --git a/src/com/android/settings/notification/NotificationPreferenceController.java b/src/com/android/settings/notification/NotificationPreferenceController.java
index 3f535fb074f..d2b7c43d8bb 100644
--- a/src/com/android/settings/notification/NotificationPreferenceController.java
+++ b/src/com/android/settings/notification/NotificationPreferenceController.java
@@ -126,6 +126,11 @@ public abstract class NotificationPreferenceController extends AbstractPreferenc
                 return mChannel.getImportance() == IMPORTANCE_NONE;
             }
 
+            if (mChannel.isImportanceLockedByOEM()
+                    || mChannel.isImportanceLockedByCriticalDeviceFunction()) {
+                return false;
+            }
+
             return mChannel.isBlockableSystem() || !mAppRow.systemApp
                     || mChannel.getImportance() == IMPORTANCE_NONE;
         }
diff --git a/tests/robotests/src/com/android/settings/notification/NotificationPreferenceControllerTest.java b/tests/robotests/src/com/android/settings/notification/NotificationPreferenceControllerTest.java
index 2368af5f94b..9c53a7bfec0 100644
--- a/tests/robotests/src/com/android/settings/notification/NotificationPreferenceControllerTest.java
+++ b/tests/robotests/src/com/android/settings/notification/NotificationPreferenceControllerTest.java
@@ -317,6 +317,30 @@ public class NotificationPreferenceControllerTest {
         assertTrue(mController.isChannelGroupBlockable());
     }
 
+    @Test
+    public void testIsChannelBlockable_oemLocked() {
+        NotificationBackend.AppRow appRow = new NotificationBackend.AppRow();
+        appRow.systemApp = false;
+        NotificationChannel channel = mock(NotificationChannel.class);
+        when(channel.isImportanceLockedByOEM()).thenReturn(true);
+        when(channel.getImportance()).thenReturn(IMPORTANCE_DEFAULT);
+
+        mController.onResume(appRow, channel, null, null);
+        assertFalse(mController.isChannelBlockable());
+    }
+
+    @Test
+    public void testIsChannelBlockable_criticalDeviceFunction() {
+        NotificationBackend.AppRow appRow = new NotificationBackend.AppRow();
+        appRow.systemApp = false;
+        NotificationChannel channel = mock(NotificationChannel.class);
+        when(channel.isImportanceLockedByCriticalDeviceFunction()).thenReturn(true);
+        when(channel.getImportance()).thenReturn(IMPORTANCE_DEFAULT);
+
+        mController.onResume(appRow, channel, null, null);
+        assertFalse(mController.isChannelBlockable());
+    }
+
     @Test
     public void testIsChannelGroupBlockable_SystemNotBlockable() {
         NotificationBackend.AppRow appRow = new NotificationBackend.AppRow();