diff --git a/CHANGELOG.md b/CHANGELOG.md
index 43e820d45b..0062161b4f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@ Important changes to data models, configuration, and migrations between each
 AppEngine version, listed here to ease deployment and troubleshooting.
 
 ## Next Release (replace with git tag when deployed)
+ * Note: accepted uncompressed archive total size is increased to 256 MiB.
 
 ## `20251120t084200-all`
  * Bump runtimeVersion to `2025.11.18`.
diff --git a/pkg/pub_package_reader/lib/pub_package_reader.dart b/pkg/pub_package_reader/lib/pub_package_reader.dart
index 15151fcb26..1321e3075f 100644
--- a/pkg/pub_package_reader/lib/pub_package_reader.dart
+++ b/pkg/pub_package_reader/lib/pub_package_reader.dart
@@ -77,10 +77,12 @@ Future<PackageSummary> summarizePackageArchive(
   /// The maximum length of the extracted content text.
   int maxContentLength = 256 * 1024,
 
-  /// The maximum file size of the archive (gzipped or compressed) and
-  /// the maximum total size of the files inside the archive.
+  /// The maximum file size of the archive (compressed).
   int maxArchiveSize = 100 * 1024 * 1024,
 
+  /// The maximum total size of the files inside the archive.
+  int maxUncompressedSize = 256 * 1024 * 1024,
+
   /// The maximum number of files in the archive.
   /// TODO: set this lower once we scan the existing archives
   int maxFileCount = 64 * 1024,
@@ -102,6 +104,7 @@ Future<PackageSummary> summarizePackageArchive(
     await scanArchiveSurface(
       archivePath,
       maxArchiveSize: maxArchiveSize,
+      maxUncompressedSize: maxUncompressedSize,
     ).toList(),
   );
   if (issues.isNotEmpty) {
diff --git a/pkg/pub_package_reader/lib/src/archive_surface.dart b/pkg/pub_package_reader/lib/src/archive_surface.dart
index c3eabc6a48..aa88a3be34 100644
--- a/pkg/pub_package_reader/lib/src/archive_surface.dart
+++ b/pkg/pub_package_reader/lib/src/archive_surface.dart
@@ -13,6 +13,7 @@ import 'package:pub_package_reader/pub_package_reader.dart' show ArchiveIssue;
 Stream<ArchiveIssue> scanArchiveSurface(
   String archivePath, {
   required int maxArchiveSize,
+  required int maxUncompressedSize,
 }) async* {
   // Some platforms may not be able to create an archive, only an empty file.
   final file = File(archivePath);
@@ -43,9 +44,9 @@ Stream<ArchiveIssue> scanArchiveSurface(
   if (uncompressedLength <= 0) {
     yield ArchiveIssue('Uncompressed archive is empty (size = 0).');
     return;
-  } else if (uncompressedLength > maxArchiveSize) {
+  } else if (uncompressedLength > maxUncompressedSize) {
     yield ArchiveIssue(
-      'Uncompressed package archive is too large (size > $maxArchiveSize).',
+      'Uncompressed package archive is too large (size > $maxUncompressedSize).',
     );
     return;
   }
diff --git a/pkg/pub_package_reader/test/archive_surface_test.dart b/pkg/pub_package_reader/test/archive_surface_test.dart
index ee8063061e..e67f30c4d4 100644
--- a/pkg/pub_package_reader/test/archive_surface_test.dart
+++ b/pkg/pub_package_reader/test/archive_surface_test.dart
@@ -84,7 +84,7 @@ void main() {
 
       final summary = await summarizePackageArchive(
         archiveFile.path,
-        maxArchiveSize: 199999,
+        maxUncompressedSize: 199999,
       );
       expect(summary.issues, isNotEmpty);
       expect(