diff --git a/tools/aapt2/Resources.proto b/tools/aapt2/Resources.proto
index ab9ce66..b1e1a77 100644
--- a/tools/aapt2/Resources.proto
+++ b/tools/aapt2/Resources.proto
@@ -168,6 +168,7 @@
     ODM = 6;
     OEM = 7;
     ACTOR = 8;
+    CONFIG_SIGNATURE = 9;
   }
 
   // The location of the <item> declaration in source.
diff --git a/tools/aapt2/format/binary/TableFlattener_test.cpp b/tools/aapt2/format/binary/TableFlattener_test.cpp
index 59627ce..6932baf 100644
--- a/tools/aapt2/format/binary/TableFlattener_test.cpp
+++ b/tools/aapt2/format/binary/TableFlattener_test.cpp
@@ -776,6 +776,7 @@
   OverlayableItem overlayable_item_three(group_one);
   overlayable_item_three.policies |= PolicyFlags::SIGNATURE;
   overlayable_item_three.policies |= PolicyFlags::ACTOR_SIGNATURE;
+  overlayable_item_three.policies |= PolicyFlags::CONFIG_SIGNATURE;
 
   std::unique_ptr<ResourceTable> table =
       test::ResourceTableBuilder()
@@ -830,7 +831,8 @@
   EXPECT_EQ(result_overlayable.overlayable->name, "OtherName");
   EXPECT_EQ(result_overlayable.overlayable->actor, "overlay://customization");
   EXPECT_EQ(result_overlayable.policies, PolicyFlags::SIGNATURE
-                                           | PolicyFlags::ACTOR_SIGNATURE);
+                                           | PolicyFlags::ACTOR_SIGNATURE
+                                           | PolicyFlags::CONFIG_SIGNATURE);
 }
 
 TEST_F(TableFlattenerTest, FlattenOverlayableNoPolicyFails) {
diff --git a/tools/aapt2/format/proto/ProtoDeserialize.cpp b/tools/aapt2/format/proto/ProtoDeserialize.cpp
index 582bd39..06ac9e5 100644
--- a/tools/aapt2/format/proto/ProtoDeserialize.cpp
+++ b/tools/aapt2/format/proto/ProtoDeserialize.cpp
@@ -404,6 +404,9 @@
       case pb::OverlayableItem::ACTOR:
         out_overlayable->policies |= PolicyFlags::ACTOR_SIGNATURE;
         break;
+      case pb::OverlayableItem::CONFIG_SIGNATURE:
+        out_overlayable->policies |= PolicyFlags::CONFIG_SIGNATURE;
+        break;
       default:
         *out_error = "unknown overlayable policy";
         return false;
diff --git a/tools/aapt2/format/proto/ProtoSerialize.cpp b/tools/aapt2/format/proto/ProtoSerialize.cpp
index 5ab43b7..98c5175 100644
--- a/tools/aapt2/format/proto/ProtoSerialize.cpp
+++ b/tools/aapt2/format/proto/ProtoSerialize.cpp
@@ -325,6 +325,9 @@
   if (overlayable_item.policies & PolicyFlags::ACTOR_SIGNATURE) {
     pb_overlayable_item->add_policy(pb::OverlayableItem::ACTOR);
   }
+  if (overlayable_item.policies & PolicyFlags::CONFIG_SIGNATURE) {
+    pb_overlayable_item->add_policy(pb::OverlayableItem::CONFIG_SIGNATURE);
+  }
 
   if (source_pool != nullptr) {
     SerializeSourceToPb(overlayable_item.source, source_pool,