diff --git a/csharp/src/Google.Protobuf/Reflection/FeatureSetDescriptor.g.cs b/csharp/src/Google.Protobuf/Reflection/FeatureSetDescriptor.g.cs
deleted file mode 100644
index 208ce1f..0000000
--- a/csharp/src/Google.Protobuf/Reflection/FeatureSetDescriptor.g.cs
+++ /dev/null
@@ -1,17 +0,0 @@
-#region Copyright notice and license
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-//
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file or at
-// https://developers.google.com/open-source/licenses/bsd
-#endregion
-
-namespace Google.Protobuf.Reflection;
-
-internal sealed partial class FeatureSetDescriptor
-{
-    // Canonical serialized form of the edition defaults, generated by embed_edition_defaults.
-    private const string DefaultsBase64 =
-        "ChMYhAciACoMCAEQAhgCIAMoATACChMY5wciACoMCAIQARgBIAIoATABChMY6AciDAgBEAEYASACKAEwASoAIOYHKOgH";
-}
diff --git a/src/google/protobuf/compiler/command_line_interface.cc b/src/google/protobuf/compiler/command_line_interface.cc
index 4458d14..edf1f90 100644
--- a/src/google/protobuf/compiler/command_line_interface.cc
+++ b/src/google/protobuf/compiler/command_line_interface.cc
@@ -1253,12 +1253,13 @@
     return EXIT_FAILURE;
   }
 
-  // Enforce extension declarations only when compiling. We want to skip
-  // this enforcement when protoc is just being invoked to encode or decode
-  // protos.
-  if (mode_ == MODE_COMPILE
-  ) {
-    descriptor_pool->EnforceExtensionDeclarations(true);
+  // Enforce extension declarations only when compiling. We want to skip this
+  // enforcement when protoc is just being invoked to encode or decode
+  // protos. If allowlist is disabled, we will not check for descriptor
+  // extensions declarations, either.
+  if (mode_ == MODE_COMPILE) {
+      descriptor_pool->EnforceExtensionDeclarations(
+          ExtDeclEnforcementLevel::kCustomExtensions);
   }
   if (!ParseInputFiles(descriptor_pool.get(), disk_source_tree.get(),
                        &parsed_files)) {
diff --git a/src/google/protobuf/descriptor.cc b/src/google/protobuf/descriptor.cc
index c9f4dc7..96130d1 100644
--- a/src/google/protobuf/descriptor.cc
+++ b/src/google/protobuf/descriptor.cc
@@ -2104,7 +2104,7 @@
       lazily_build_dependencies_(false),
       allow_unknown_(false),
       enforce_weak_(false),
-      enforce_extension_declarations_(false),
+      enforce_extension_declarations_(ExtDeclEnforcementLevel::kNoEnforcement),
       disallow_enforce_utf8_(false),
       deprecated_legacy_json_field_conflicts_(false) {}
 
@@ -2119,7 +2119,7 @@
       lazily_build_dependencies_(false),
       allow_unknown_(false),
       enforce_weak_(false),
-      enforce_extension_declarations_(false),
+      enforce_extension_declarations_(ExtDeclEnforcementLevel::kNoEnforcement),
       disallow_enforce_utf8_(false),
       deprecated_legacy_json_field_conflicts_(false) {}
 
@@ -2133,7 +2133,7 @@
       lazily_build_dependencies_(false),
       allow_unknown_(false),
       enforce_weak_(false),
-      enforce_extension_declarations_(false),
+      enforce_extension_declarations_(ExtDeclEnforcementLevel::kNoEnforcement),
       disallow_enforce_utf8_(false),
       deprecated_legacy_json_field_conflicts_(false) {}
 
@@ -8045,7 +8045,7 @@
       return;
     }
 
-    if (pool_->enforce_extension_declarations_) {
+    if (pool_->EnforceCustomExtensionDeclarations()) {
       for (const auto& declaration : extension_range->options_->declaration()) {
         if (declaration.number() != field->number()) continue;
         if (declaration.reserved()) {
diff --git a/src/google/protobuf/descriptor.h b/src/google/protobuf/descriptor.h
index 1222bac..d30a6ff 100644
--- a/src/google/protobuf/descriptor.h
+++ b/src/google/protobuf/descriptor.h
@@ -2041,6 +2041,18 @@
 
 PROTOBUF_INTERNAL_CHECK_CLASS_SIZE(FileDescriptor, 168);
 
+#ifndef SWIG
+enum class ExtDeclEnforcementLevel : uint8_t {
+  // No enforcement.
+  kNoEnforcement = 0,
+  // All extensions excluding descriptor.proto extensions
+  // (go/extension-declarations#descriptor-proto)
+  kCustomExtensions = 1,
+  // All extensions including descriptor.proto extensions.
+  kAllExtensions = 2,
+};
+#endif  // !SWIG
+
 // ===================================================================
 
 // Used to construct descriptors.
@@ -2266,10 +2278,22 @@
   // This enforcement is disabled by default because it requires full
   // descriptors with source-retention options, which are generally not
   // available at runtime.
-  void EnforceExtensionDeclarations(bool enforce) {
+  void EnforceExtensionDeclarations(google::protobuf::ExtDeclEnforcementLevel enforce) {
     enforce_extension_declarations_ = enforce;
   }
 
+  bool EnforceDescriptorExtensionDeclarations() const {
+    return enforce_extension_declarations_ ==
+           ExtDeclEnforcementLevel::kAllExtensions;
+  }
+
+  bool EnforceCustomExtensionDeclarations() const {
+    return enforce_extension_declarations_ ==
+               ExtDeclEnforcementLevel::kAllExtensions ||
+           enforce_extension_declarations_ ==
+               ExtDeclEnforcementLevel::kCustomExtensions;
+  }
+
 #ifndef SWIG
   // Dispatch recursive builds to a callback that may stick them onto a separate
   // thread.  This is primarily to avoid stack overflows on untrusted inputs.
@@ -2484,7 +2508,7 @@
   bool lazily_build_dependencies_;
   bool allow_unknown_;
   bool enforce_weak_;
-  bool enforce_extension_declarations_;
+  ExtDeclEnforcementLevel enforce_extension_declarations_;
   bool disallow_enforce_utf8_;
   bool deprecated_legacy_json_field_conflicts_;
   mutable bool build_started_ = false;
diff --git a/src/google/protobuf/descriptor_unittest.cc b/src/google/protobuf/descriptor_unittest.cc
index 5878524..17eddae 100644
--- a/src/google/protobuf/descriptor_unittest.cc
+++ b/src/google/protobuf/descriptor_unittest.cc
@@ -4300,7 +4300,7 @@
   void SetUp() override {
     // Enable extension declaration enforcement since most test cases want to
     // exercise the full validation.
-    pool_.EnforceExtensionDeclarations(true);
+    pool_.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   }
   // Parse file_text as a FileDescriptorProto in text format and add it
   // to the DescriptorPool.  Expect no errors.
@@ -11735,7 +11735,7 @@
   // Make sure that extension declaration names and types are not validated
   // outside of protoc. This is important for allowing extensions to be renamed
   // safely.
-  pool_.EnforceExtensionDeclarations(false);
+  pool_.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kNoEnforcement);
   BuildFile(
       R"pb(
         name: "foo.proto"
@@ -11921,7 +11921,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   EXPECT_NE(pool.BuildFile(*file_proto), nullptr);
 }
 
@@ -11954,7 +11954,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   EXPECT_NE(pool.BuildFile(*file_proto), nullptr);
 }
 
@@ -11991,7 +11991,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   MockErrorCollector error_collector;
   EXPECT_EQ(pool.BuildFileCollectingErrors(*file_proto, &error_collector),
             nullptr);
@@ -12027,7 +12027,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   EXPECT_NE(pool.BuildFile(*file_proto), nullptr);
 }
 
@@ -12056,7 +12056,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   MockErrorCollector error_collector;
   EXPECT_EQ(pool.BuildFileCollectingErrors(*file_proto, &error_collector),
             nullptr);
@@ -12086,7 +12086,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   MockErrorCollector error_collector;
   EXPECT_EQ(pool.BuildFileCollectingErrors(*file_proto, &error_collector),
             nullptr);
@@ -12121,7 +12121,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   MockErrorCollector error_collector;
   EXPECT_EQ(pool.BuildFileCollectingErrors(*file_proto, &error_collector),
             nullptr);
@@ -12151,7 +12151,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   EXPECT_NE(pool.BuildFile(*file_proto), nullptr);
 }
 
@@ -12180,7 +12180,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   MockErrorCollector error_collector;
   EXPECT_EQ(pool.BuildFileCollectingErrors(*file_proto, &error_collector),
             nullptr);
@@ -12215,7 +12215,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   MockErrorCollector error_collector;
   EXPECT_EQ(pool.BuildFileCollectingErrors(*file_proto, &error_collector),
             nullptr);
@@ -12255,7 +12255,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   MockErrorCollector error_collector;
   EXPECT_EQ(pool.BuildFileCollectingErrors(*file_proto, &error_collector),
             nullptr);
@@ -12287,7 +12287,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   MockErrorCollector error_collector;
   EXPECT_EQ(pool.BuildFileCollectingErrors(*file_proto, &error_collector),
             nullptr);
@@ -12333,7 +12333,7 @@
   ASSERT_OK(file_proto);
 
   DescriptorPool pool;
-  pool.EnforceExtensionDeclarations(true);
+  pool.EnforceExtensionDeclarations(ExtDeclEnforcementLevel::kAllExtensions);
   EXPECT_NE(pool.BuildFile(*file_proto), nullptr);
 }