diff --git a/libs/gui/ISurfaceComposer.cpp b/libs/gui/ISurfaceComposer.cpp
index 2a980bd..1726761 100644
--- a/libs/gui/ISurfaceComposer.cpp
+++ b/libs/gui/ISurfaceComposer.cpp
@@ -292,6 +292,17 @@
         return {};
     }
 
+    status_t getPrimaryPhysicalDisplayId(PhysicalDisplayId* displayId) const override {
+        Parcel data, reply;
+        SAFE_PARCEL(data.writeInterfaceToken, ISurfaceComposer::getInterfaceDescriptor());
+        SAFE_PARCEL(remote()->transact, BnSurfaceComposer::GET_PRIMARY_PHYSICAL_DISPLAY_ID, data,
+                    &reply);
+        uint64_t rawId;
+        SAFE_PARCEL(reply.readUint64, &rawId);
+        *displayId = PhysicalDisplayId(rawId);
+        return NO_ERROR;
+    }
+
     sp<IBinder> getPhysicalDisplayToken(PhysicalDisplayId displayId) const override {
         Parcel data, reply;
         data.writeInterfaceToken(ISurfaceComposer::getInterfaceDescriptor());
@@ -1730,6 +1741,16 @@
                            [](PhysicalDisplayId id) { return id.value; });
             return reply->writeUint64Vector(rawIds);
         }
+        case GET_PRIMARY_PHYSICAL_DISPLAY_ID: {
+            CHECK_INTERFACE(ISurfaceComposer, data, reply);
+            PhysicalDisplayId id;
+            status_t result = getPrimaryPhysicalDisplayId(&id);
+            if (result != NO_ERROR) {
+                ALOGE("getPrimaryPhysicalDisplayId: Failed to get id");
+                return result;
+            }
+            return reply->writeUint64(id.value);
+        }
         case ADD_REGION_SAMPLING_LISTENER: {
             CHECK_INTERFACE(ISurfaceComposer, data, reply);
             Rect samplingArea;