--- a/net/minecraft/server/packs/repository/ServerPacksSource.java
+++ b/net/minecraft/server/packs/repository/ServerPacksSource.java
@@ -48,7 +48,7 @@
     public static VanillaPackResources createVanillaPackSource() {
         return new VanillaPackResourcesBuilder()
             .setMetadata(BUILT_IN_METADATA)
-            .exposeNamespace("minecraft")
+            .exposeNamespace("minecraft", ResourceLocation.PAPER_NAMESPACE) // Paper
             .applyDevelopmentConfig()
             .pushJarResources()
             .build(VANILLA_PACK_INFO);
@@ -68,7 +68,18 @@
     @Nullable
     @Override
     protected Pack createBuiltinPack(String fileName, Pack.ResourcesSupplier packFactory, Component displayName) {
-        return Pack.readMetaAndCreate(createBuiltInPackLocation(fileName, displayName), packFactory, PackType.SERVER_DATA, FEATURE_SELECTION_CONFIG);
+        // Paper start - custom built-in pack
+        final PackLocationInfo info;
+        final PackSelectionConfig packConfig;
+        if ("paper".equals(fileName)) {
+            info = new PackLocationInfo(fileName, displayName, PackSource.BUILT_IN, Optional.empty());
+            packConfig = new PackSelectionConfig(true, Pack.Position.TOP, true);
+        } else {
+            info = createBuiltInPackLocation(fileName, displayName);
+            packConfig = FEATURE_SELECTION_CONFIG;
+        }
+        return Pack.readMetaAndCreate(info, packFactory, PackType.SERVER_DATA, packConfig);
+        // Paper end - custom built-in pack
     }
 
     public static PackRepository createPackRepository(Path dataPacksPath, DirectoryValidator symlinkFinder) {
