diff --git a/.gitignore b/.gitignore
index e31152a..28a415f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@ Makefile.in
 /py-compile
 /test-driver
 /ylwrap
+/build
 
 /autom4te.cache
 /autoscan.log
diff --git a/src/common.h b/src/common.h
index d7e7554..e08f6de 100644
--- a/src/common.h
+++ b/src/common.h
@@ -64,12 +64,6 @@ static constexpr int64 kint64max = ((int64)(0x7FFFFFFFFFFFFFFF));
 
 static constexpr uint32 kUnicodeError = 0xFFFD;
 
-#ifdef OS_WIN
-#define OUTPUT_MODE std::ios::binary | std::ios::out
-#else
-#define OUTPUT_MODE std::ios::out
-#endif
-
 #if defined(OS_WIN) && defined(UNICODE) && defined(_UNICODE)
 #define WPATH(path) (::sentencepiece::win32::Utf8ToWide(path).c_str())
 #else
diff --git a/src/filesystem.cc b/src/filesystem.cc
index 12bd600..2bf2bbb 100644
--- a/src/filesystem.cc
+++ b/src/filesystem.cc
@@ -13,8 +13,16 @@
 // limitations under the License.!
 
 #include "filesystem.h"
+#include <iostream>
+
 #include "util.h"
 
+#ifdef OS_WIN
+#define OUTPUT_MODE std::ios::binary | std::ios::out
+#else
+#define OUTPUT_MODE std::ios::out
+#endif
+
 namespace sentencepiece {
 namespace filesystem {
 
@@ -38,7 +46,15 @@ class PosixReadableFile : public ReadableFile {
     return static_cast<bool>(std::getline(*is_, *line));
   }
 
-  bool ReadAll(std::string *line) { return true; }
+  bool ReadAll(std::string *line) {
+    if (is_ == &std::cin) {
+      LOG(ERROR) << "ReadAll is not supported for stdin.";
+      return false;
+    }
+    line->assign(std::istreambuf_iterator<char>(*is_),
+                 std::istreambuf_iterator<char>());
+    return true;
+  }
 
  private:
   util::Status status_;
@@ -72,7 +88,7 @@ class PosixWritableFile : public WritableFile {
  private:
   util::Status status_;
   std::ostream *os_;
-};  // namespace filesystem
+};
 
 std::unique_ptr<ReadableFile> NewReadableFile(absl::string_view filename) {
   return port::MakeUnique<PosixReadableFile>(filename);
diff --git a/src/sentencepiece_processor.cc b/src/sentencepiece_processor.cc
index 50f3f4b..1e2ddcb 100644
--- a/src/sentencepiece_processor.cc
+++ b/src/sentencepiece_processor.cc
@@ -43,13 +43,11 @@ SentencePieceProcessor::SentencePieceProcessor() {}
 SentencePieceProcessor::~SentencePieceProcessor() {}
 
 util::Status SentencePieceProcessor::Load(util::min_string_view filename) {
-  std::ifstream ifs(WPATH(filename.data()), std::ios::binary | std::ios::in);
-  if (!ifs) {
-    return util::StatusBuilder(util::error::NOT_FOUND)
-           << "\"" << filename.data() << "\": " << util::StrError(errno);
-  }
-
-  return Load(&ifs);
+  auto input = filesystem::NewReadableFile(string_util::ToSV(filename));
+  RETURN_IF_ERROR(input->status());
+  std::string proto;
+  CHECK_OR_RETURN(input->ReadAll(&proto));
+  return LoadFromSerializedProto(proto);
 }
 
 void SentencePieceProcessor::LoadOrDie(util::min_string_view filename) {
@@ -57,10 +55,9 @@ void SentencePieceProcessor::LoadOrDie(util::min_string_view filename) {
 }
 
 util::Status SentencePieceProcessor::Load(std::istream *is) {
-  CHECK_OR_RETURN(is) << "input ifstream is null";
-  auto model_proto = port::MakeUnique<ModelProto>();
-  CHECK_OR_RETURN(model_proto->ParseFromIstream(is)) << "Model file is broken";
-  return Load(std::move(model_proto));
+  return util::StatusBuilder(util::error::UNIMPLEMENTED)
+         << "std::stream API is deprecated. Use LoadFromSerializedProto() "
+         << "to load model from any serialized blob object.";
 }
 
 util::Status SentencePieceProcessor::Load(const ModelProto &model_proto) {
diff --git a/src/util.h b/src/util.h
index fb88999..4d940cf 100644
--- a/src/util.h
+++ b/src/util.h
@@ -19,7 +19,6 @@
 #include <string.h>
 
 #include <algorithm>
-#include <fstream>
 #include <memory>
 #include <random>
 #include <sstream>