diff --git a/td/telegram/files/FileUploader.cpp b/td/telegram/files/FileUploader.cpp
index c4b7809f..d83d9022 100644
--- a/td/telegram/files/FileUploader.cpp
+++ b/td/telegram/files/FileUploader.cpp
@@ -277,12 +277,10 @@ Result<std::pair<NetQueryPtr, bool>> FileUploader::start_part(Part part, int32 p
   if (big_flag_) {
     auto query =
         telegram_api::upload_saveBigFilePart(file_id_, part.id, local_is_ready_ ? part_count : -1, std::move(bytes));
-    net_query = G()->net_query_creator().create(create_storer(query), DcId::main(), NetQuery::Type::Upload,
-                                                NetQuery::AuthFlag::On, NetQuery::GzipFlag::Off);
+    net_query = G()->net_query_creator().create(create_storer(query), DcId::main(), NetQuery::Type::Upload);
   } else {
     auto query = telegram_api::upload_saveFilePart(file_id_, part.id, std::move(bytes));
-    net_query = G()->net_query_creator().create(create_storer(query), DcId::main(), NetQuery::Type::Upload,
-                                                NetQuery::AuthFlag::On, NetQuery::GzipFlag::Off);
+    net_query = G()->net_query_creator().create(create_storer(query), DcId::main(), NetQuery::Type::Upload);
   }
   net_query->file_type_ = narrow_cast<int32>(file_type_);
   return std::make_pair(std::move(net_query), false);
diff --git a/td/telegram/net/NetQueryCreator.cpp b/td/telegram/net/NetQueryCreator.cpp
index 9e2f0564..f3b801ab 100644
--- a/td/telegram/net/NetQueryCreator.cpp
+++ b/td/telegram/net/NetQueryCreator.cpp
@@ -14,19 +14,26 @@
 namespace td {
 
 NetQueryCreator::Ptr NetQueryCreator::create(uint64 id, const Storer &storer, DcId dc_id, NetQuery::Type type,
-                                             NetQuery::AuthFlag auth_flag, NetQuery::GzipFlag gzip_flag) {
+                                             NetQuery::AuthFlag auth_flag) {
   BufferSlice slice(storer.size());
   auto real_size = storer.store(slice.as_slice().ubegin());
   LOG_CHECK(real_size == slice.size()) << real_size << " " << slice.size() << " "
                                        << format::as_hex_dump<4>(Slice(slice.as_slice()));
 
-  // TODO: magic constant
-  if (slice.size() < (1 << 8)) {
-    gzip_flag = NetQuery::GzipFlag::Off;
-  }
   int32 tl_constructor = NetQuery::tl_magic(slice);
+
+  size_t MIN_GZIPPED_SIZE = 128;
+  auto gzip_flag = slice.size() < MIN_GZIPPED_SIZE ? NetQuery::GzipFlag::Off : NetQuery::GzipFlag::On;
+  if (slice.size() >= 16384) {
+    // test compression ratio for the middle part
+    // if it is less than 0.9, then try to compress the whole request
+    size_t TESTED_SIZE = 1024;
+    BufferSlice compressed_part = gzencode(slice.as_slice().substr((slice.size() - TESTED_SIZE) / 2, TESTED_SIZE), 0.9);
+    if (compressed_part.empty()) {
+      gzip_flag = NetQuery::GzipFlag::Off;
+    }
+  }
   if (gzip_flag == NetQuery::GzipFlag::On) {
-    // TODO: try to compress files?
     BufferSlice compressed = gzencode(slice.as_slice(), 0.9);
     if (compressed.empty()) {
       gzip_flag = NetQuery::GzipFlag::Off;
diff --git a/td/telegram/net/NetQueryCreator.h b/td/telegram/net/NetQueryCreator.h
index 353eebe3..98fd1e21 100644
--- a/td/telegram/net/NetQueryCreator.h
+++ b/td/telegram/net/NetQueryCreator.h
@@ -35,13 +35,11 @@ class NetQueryCreator {
   }
 
   Ptr create(const Storer &storer, DcId dc_id = DcId::main(), NetQuery::Type type = NetQuery::Type::Common,
-             NetQuery::AuthFlag auth_flag = NetQuery::AuthFlag::On,
-             NetQuery::GzipFlag gzip_flag = NetQuery::GzipFlag::On) {
-    return create(UniqueId::next(), storer, dc_id, type, auth_flag, gzip_flag);
+             NetQuery::AuthFlag auth_flag = NetQuery::AuthFlag::On) {
+    return create(UniqueId::next(), storer, dc_id, type, auth_flag);
   }
   Ptr create(uint64 id, const Storer &storer, DcId dc_id = DcId::main(), NetQuery::Type type = NetQuery::Type::Common,
-             NetQuery::AuthFlag auth_flag = NetQuery::AuthFlag::On,
-             NetQuery::GzipFlag gzip_flag = NetQuery::GzipFlag::On);
+             NetQuery::AuthFlag auth_flag = NetQuery::AuthFlag::On);
 
  private:
   ObjectPool<NetQuery> object_pool_;