diff --git a/quiche/http2/adapter/nghttp2_adapter_test.cc b/quiche/http2/adapter/nghttp2_adapter_test.cc
index 8647b02..8751f52 100644
--- a/quiche/http2/adapter/nghttp2_adapter_test.cc
+++ b/quiche/http2/adapter/nghttp2_adapter_test.cc
@@ -5883,12 +5883,12 @@
   EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::SETTINGS}));
 }
 
-TEST(NgHttp2AdapterTest, InvalidMaxFrameSize) {
+TEST(NgHttp2AdapterTest, InvalidMaxFrameSizeSetting) {
   DataSavingVisitor visitor;
   auto adapter = NgHttp2Adapter::CreateServerAdapter(visitor);
 
   const std::string frames =
-      TestFrameSequence().ClientPreface({{MAX_FRAME_SIZE, 3}}).Serialize();
+      TestFrameSequence().ClientPreface({{MAX_FRAME_SIZE, 3u}}).Serialize();
   testing::InSequence s;
 
   // Client preface
@@ -5912,6 +5912,90 @@
   EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::GOAWAY}));
 }
 
+TEST(OgHttp2AdapterTest, InvalidPushSetting) {
+  DataSavingVisitor visitor;
+  auto adapter = NgHttp2Adapter::CreateServerAdapter(visitor);
+
+  const std::string frames =
+      TestFrameSequence().ClientPreface({{ENABLE_PUSH, 3u}}).Serialize();
+  testing::InSequence s;
+
+  // Client preface
+  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
+  EXPECT_CALL(visitor, OnInvalidFrame(0, _));
+
+  const int64_t read_result = adapter->ProcessBytes(frames);
+  EXPECT_EQ(static_cast<size_t>(read_result), frames.size());
+
+  EXPECT_TRUE(adapter->want_write());
+
+  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
+  EXPECT_CALL(visitor,
+              OnFrameSent(GOAWAY, 0, _, 0x0,
+                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
+
+  int send_result = adapter->Send();
+  EXPECT_EQ(0, send_result);
+  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::GOAWAY}));
+}
+
+TEST(NgHttp2AdapterTest, InvalidConnectProtocolSetting) {
+  DataSavingVisitor visitor;
+  auto adapter = NgHttp2Adapter::CreateServerAdapter(visitor);
+
+  const std::string frames = TestFrameSequence()
+                                 .ClientPreface({{ENABLE_CONNECT_PROTOCOL, 3u}})
+                                 .Serialize();
+  testing::InSequence s;
+
+  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
+  EXPECT_CALL(
+      visitor,
+      OnInvalidFrame(0, Http2VisitorInterface::InvalidFrameError::kProtocol));
+
+  int64_t read_result = adapter->ProcessBytes(frames);
+  EXPECT_EQ(static_cast<size_t>(read_result), frames.size());
+
+  EXPECT_TRUE(adapter->want_write());
+
+  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
+  EXPECT_CALL(visitor,
+              OnFrameSent(GOAWAY, 0, _, 0x0,
+                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
+
+  int send_result = adapter->Send();
+  EXPECT_EQ(0, send_result);
+  EXPECT_THAT(visitor.data(), EqualsFrames({SpdyFrameType::GOAWAY}));
+
+  auto adapter2 = NgHttp2Adapter::CreateServerAdapter(visitor);
+  const std::string frames2 = TestFrameSequence()
+                                  .ClientPreface({{ENABLE_CONNECT_PROTOCOL, 1}})
+                                  .Settings({{ENABLE_CONNECT_PROTOCOL, 0}})
+                                  .Serialize();
+
+  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
+  EXPECT_CALL(visitor, OnSettingsStart());
+  EXPECT_CALL(visitor, OnSetting(Http2Setting{ENABLE_CONNECT_PROTOCOL, 1u}));
+  EXPECT_CALL(visitor, OnSettingsEnd());
+  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
+  EXPECT_CALL(visitor, OnSettingsStart());
+  // Surprisingly, nghttp2 allows this behavior, which is prohibited in RFC
+  // 8441.
+  EXPECT_CALL(visitor, OnSetting(Http2Setting{ENABLE_CONNECT_PROTOCOL, 0u}));
+  EXPECT_CALL(visitor, OnSettingsEnd());
+
+  read_result = adapter2->ProcessBytes(frames2);
+  EXPECT_EQ(static_cast<size_t>(read_result), frames2.size());
+
+  EXPECT_TRUE(adapter2->want_write());
+
+  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
+  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
+  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x1));
+  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x1, 0));
+  adapter2->Send();
+}
+
 TEST(NgHttp2AdapterTest, ServerForbidsProtocolPseudoheaderBeforeAck) {
   DataSavingVisitor visitor;
   auto adapter = NgHttp2Adapter::CreateServerAdapter(visitor);
diff --git a/quiche/http2/adapter/oghttp2_adapter_test.cc b/quiche/http2/adapter/oghttp2_adapter_test.cc
index ba195bc..ca6333f 100644
--- a/quiche/http2/adapter/oghttp2_adapter_test.cc
+++ b/quiche/http2/adapter/oghttp2_adapter_test.cc
@@ -347,14 +347,14 @@
               EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::SETTINGS}));
 }
 
-TEST(OgHttp2AdapterTest, InvalidMaxFrameSize) {
+TEST(OgHttp2AdapterTest, InvalidMaxFrameSizeSetting) {
   DataSavingVisitor visitor;
   OgHttp2Adapter::Options options;
   options.perspective = Perspective::kServer;
   auto adapter = OgHttp2Adapter::Create(visitor, options);
 
   const std::string frames =
-      TestFrameSequence().ClientPreface({{MAX_FRAME_SIZE, 3}}).Serialize();
+      TestFrameSequence().ClientPreface({{MAX_FRAME_SIZE, 3u}}).Serialize();
   testing::InSequence s;
 
   // Client preface
@@ -383,6 +383,108 @@
               EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
 }
 
+TEST(OgHttp2AdapterTest, InvalidPushSetting) {
+  DataSavingVisitor visitor;
+  OgHttp2Adapter::Options options;
+  options.perspective = Perspective::kServer;
+  auto adapter = OgHttp2Adapter::Create(visitor, options);
+
+  const std::string frames =
+      TestFrameSequence().ClientPreface({{ENABLE_PUSH, 3u}}).Serialize();
+  testing::InSequence s;
+
+  // Client preface
+  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
+  EXPECT_CALL(visitor, OnSettingsStart());
+  EXPECT_CALL(
+      visitor,
+      OnInvalidFrame(0, Http2VisitorInterface::InvalidFrameError::kProtocol));
+  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kInvalidSetting));
+
+  const int64_t read_result = adapter->ProcessBytes(frames);
+  EXPECT_EQ(static_cast<size_t>(read_result), frames.size());
+
+  EXPECT_TRUE(adapter->want_write());
+
+  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
+  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
+  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
+  EXPECT_CALL(visitor,
+              OnFrameSent(GOAWAY, 0, _, 0x0,
+                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
+
+  int send_result = adapter->Send();
+  EXPECT_EQ(0, send_result);
+  EXPECT_THAT(visitor.data(),
+              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
+}
+
+TEST(OgHttp2AdapterTest, InvalidConnectProtocolSetting) {
+  DataSavingVisitor visitor;
+  OgHttp2Adapter::Options options;
+  options.perspective = Perspective::kServer;
+  auto adapter = OgHttp2Adapter::Create(visitor, options);
+
+  const std::string frames = TestFrameSequence()
+                                 .ClientPreface({{ENABLE_CONNECT_PROTOCOL, 3u}})
+                                 .Serialize();
+  testing::InSequence s;
+
+  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
+  EXPECT_CALL(visitor, OnSettingsStart());
+  EXPECT_CALL(
+      visitor,
+      OnInvalidFrame(0, Http2VisitorInterface::InvalidFrameError::kProtocol));
+  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kInvalidSetting));
+
+  int64_t read_result = adapter->ProcessBytes(frames);
+  EXPECT_EQ(static_cast<size_t>(read_result), frames.size());
+
+  EXPECT_TRUE(adapter->want_write());
+
+  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
+  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
+  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
+  EXPECT_CALL(visitor,
+              OnFrameSent(GOAWAY, 0, _, 0x0,
+                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
+
+  int send_result = adapter->Send();
+  EXPECT_EQ(0, send_result);
+  EXPECT_THAT(visitor.data(),
+              EqualsFrames({SpdyFrameType::SETTINGS, SpdyFrameType::GOAWAY}));
+
+  auto adapter2 = OgHttp2Adapter::Create(visitor, options);
+  const std::string frames2 = TestFrameSequence()
+                                  .ClientPreface({{ENABLE_CONNECT_PROTOCOL, 1}})
+                                  .Settings({{ENABLE_CONNECT_PROTOCOL, 0}})
+                                  .Serialize();
+
+  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
+  EXPECT_CALL(visitor, OnSettingsStart());
+  EXPECT_CALL(visitor, OnSetting(Http2Setting{ENABLE_CONNECT_PROTOCOL, 1u}));
+  EXPECT_CALL(visitor, OnSettingsEnd());
+  EXPECT_CALL(visitor, OnFrameHeader(0, 6, SETTINGS, 0));
+  EXPECT_CALL(visitor, OnSettingsStart());
+  EXPECT_CALL(
+      visitor,
+      OnInvalidFrame(0, Http2VisitorInterface::InvalidFrameError::kProtocol));
+  EXPECT_CALL(visitor, OnConnectionError(ConnectionError::kInvalidSetting));
+
+  read_result = adapter2->ProcessBytes(frames2);
+  EXPECT_EQ(static_cast<size_t>(read_result), frames2.size());
+
+  EXPECT_TRUE(adapter2->want_write());
+
+  EXPECT_CALL(visitor, OnBeforeFrameSent(SETTINGS, 0, _, 0x0));
+  EXPECT_CALL(visitor, OnFrameSent(SETTINGS, 0, _, 0x0, 0));
+  EXPECT_CALL(visitor, OnBeforeFrameSent(GOAWAY, 0, _, 0x0));
+  EXPECT_CALL(visitor,
+              OnFrameSent(GOAWAY, 0, _, 0x0,
+                          static_cast<int>(Http2ErrorCode::PROTOCOL_ERROR)));
+  adapter2->Send();
+}
+
 TEST(OgHttp2AdapterTest, ClientHandles100Headers) {
   DataSavingVisitor visitor;
   OgHttp2Adapter::Options options;
diff --git a/quiche/http2/adapter/oghttp2_session.cc b/quiche/http2/adapter/oghttp2_session.cc
index 9f48090..89fc1df 100644
--- a/quiche/http2/adapter/oghttp2_session.cc
+++ b/quiche/http2/adapter/oghttp2_session.cc
@@ -1233,6 +1233,18 @@
         encoder_header_table_capacity_when_acking_ = value;
       }
       break;
+    case ENABLE_PUSH:
+      if (value > 1u) {
+        visitor_.OnInvalidFrame(
+            0, Http2VisitorInterface::InvalidFrameError::kProtocol);
+        // The specification says this is a connection-level protocol error.
+        LatchErrorAndNotify(
+            Http2ErrorCode::PROTOCOL_ERROR,
+            Http2VisitorInterface::ConnectionError::kInvalidSetting);
+        return;
+      }
+      // Aside from validation, this setting is ignored.
+      break;
     case MAX_CONCURRENT_STREAMS:
       max_outbound_concurrent_streams_ = value;
       if (!IsServerSession()) {
@@ -1266,6 +1278,17 @@
       }
       max_frame_payload_ = value;
       break;
+    case ENABLE_CONNECT_PROTOCOL:
+      if (value > 1u || (value == 0 && peer_enables_connect_protocol_)) {
+        visitor_.OnInvalidFrame(
+            0, Http2VisitorInterface::InvalidFrameError::kProtocol);
+        LatchErrorAndNotify(
+            Http2ErrorCode::PROTOCOL_ERROR,
+            Http2VisitorInterface::ConnectionError::kInvalidSetting);
+        return;
+      }
+      peer_enables_connect_protocol_ = (value == 1u);
+      break;
     default:
       // TODO(bnc): See if C++17 inline constants are allowed in QUICHE.
       if (id == kMetadataExtensionId) {
diff --git a/quiche/http2/adapter/oghttp2_session.h b/quiche/http2/adapter/oghttp2_session.h
index b4d713b..25b7f52 100644
--- a/quiche/http2/adapter/oghttp2_session.h
+++ b/quiche/http2/adapter/oghttp2_session.h
@@ -153,6 +153,9 @@
             !goaway_rejected_streams_.empty());
   }
   int GetRemoteWindowSize() const override { return connection_send_window_; }
+  bool peer_enables_connect_protocol() {
+    return peer_enables_connect_protocol_;
+  }
 
   // From SpdyFramerVisitorInterface
   void OnError(http2::Http2DecoderAdapter::SpdyFramerError error,
@@ -508,7 +511,7 @@
   int32_t initial_stream_receive_window_ = kInitialFlowControlWindowSize;
   // The initial flow control send window size for any newly created streams.
   int32_t initial_stream_send_window_ = kInitialFlowControlWindowSize;
-  uint32_t max_frame_payload_ = 16384u;
+  uint32_t max_frame_payload_ = kDefaultFramePayloadSizeLimit;
   // The maximum number of concurrent streams that this connection can open to
   // its peer and allow from its peer, respectively. Although the initial value
   // is unlimited, the spec encourages a value of at least 100. We limit
@@ -537,6 +540,8 @@
   // Recursion guard for Send().
   bool sending_ = false;
 
+  bool peer_enables_connect_protocol_ = false;
+
   // Replace this with a stream ID, for multiple GOAWAY support.
   bool queued_goaway_ = false;
   bool queued_immediate_goaway_ = false;