diff --git a/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredRuleClassProvider.java b/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredRuleClassProvider.java
index fc0e83a..7ad8850 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredRuleClassProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/ConfiguredRuleClassProvider.java
@@ -56,6 +56,7 @@
 import com.google.devtools.build.lib.starlarkbuildapi.core.Bootstrap;
 import com.google.devtools.build.lib.vfs.DigestHashFunction;
 import com.google.devtools.build.lib.vfs.Path;
+import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.lib.vfs.Root;
 import com.google.devtools.build.lib.vfs.inmemoryfs.InMemoryFileSystem;
 import com.google.devtools.common.options.Option;
@@ -103,6 +104,31 @@
     ImmutableList<RuleSet> requires();
   }
 
+  /** An InMemoryFileSystem for bundled builtins .bzl files. */
+  public static class BundledFileSystem extends InMemoryFileSystem {
+
+    private static final byte[] EMPTY_DIGEST = new byte[0];
+
+    public BundledFileSystem() {
+      super(DigestHashFunction.SHA256);
+    }
+
+    // Bundled files are guaranteed to not change throughout the lifetime of the Bazel server, so it
+    // is permissible to use a fake digest. This helps avoid peculiarities in the interaction of
+    // InMemoryFileSystem and Skyframe. See cl/354809138 for further discussion, including of
+    // possible (but unlikely) future caveats of this approach.
+
+    @Override
+    protected synchronized byte[] getFastDigest(PathFragment path) throws IOException {
+      return EMPTY_DIGEST;
+    }
+
+    @Override
+    protected synchronized byte[] getDigest(PathFragment path) throws IOException {
+      return EMPTY_DIGEST;
+    }
+  }
+
   /** Builder for {@link ConfiguredRuleClassProvider}. */
   public static class Builder implements RuleDefinitionEnvironment {
     private final StringBuilder defaultWorkspaceFilePrefix = new StringBuilder();
@@ -503,7 +529,7 @@
         // Use of --experimental_builtins_bzl_path=%bundled% is disallowed.
         builtinsRoot = null;
       } else {
-        InMemoryFileSystem fs = new InMemoryFileSystem(DigestHashFunction.SHA256);
+        BundledFileSystem fs = new BundledFileSystem();
         Path builtinsPath = fs.getPath("/virtual_builtins_bzl");
         if (builtinsBzlZipResource != null) {
           // Production case.
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ExternalFilesHelper.java b/src/main/java/com/google/devtools/build/lib/skyframe/ExternalFilesHelper.java
index c4e85d1..da07b4d 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ExternalFilesHelper.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ExternalFilesHelper.java
@@ -16,6 +16,7 @@
 import com.google.common.base.Preconditions;
 import com.google.common.flogger.GoogleLogger;
 import com.google.devtools.build.lib.analysis.BlazeDirectories;
+import com.google.devtools.build.lib.analysis.ConfiguredRuleClassProvider.BundledFileSystem;
 import com.google.devtools.build.lib.cmdline.LabelConstants;
 import com.google.devtools.build.lib.cmdline.RepositoryName;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadCompatible;
@@ -151,6 +152,13 @@
 
   /** Classification of a path encountered by Bazel. */
   public enum FileType {
+    /**
+     * A path to a file located inside of Bazel, e.g. the bundled builtins_bzl root (for {@code
+     * --experimental_builtins_bzl_root=%bundled%}) that live in an InMemoryFileSystem. These files
+     * must not change throughout the lifetime of the server.
+     */
+    BUNDLED,
+
     /** A path inside the package roots. */
     INTERNAL,
 
@@ -259,7 +267,14 @@
     return Pair.of(fileType, null);
   }
 
+  /**
+   * Returns the classification of a path, and updates this instance's state regarding what kinds of
+   * paths have been seen.
+   */
   private FileType detectFileType(RootedPath rootedPath) {
+    if (rootedPath.getRoot().getFileSystem() instanceof BundledFileSystem) {
+      return FileType.BUNDLED;
+    }
     PathPackageLocator packageLocator = pkgLocator.get();
     if (packageLocator.getPathEntries().contains(rootedPath.getRoot())) {
       return FileType.INTERNAL;
@@ -305,6 +320,7 @@
             externalFileAction);
         RepositoryFunction.addManagedDirectoryDependencies(pair.getSecond(), env);
         break;
+      case BUNDLED:
       case INTERNAL:
         break;
       case EXTERNAL: