diff --git a/sf-buffer/test/test_BufferBinaryWriter.cpp b/sf-buffer/test/test_BufferBinaryWriter.cpp
index d84eb14..eee5557 100644
--- a/sf-buffer/test/test_BufferBinaryWriter.cpp
+++ b/sf-buffer/test/test_BufferBinaryWriter.cpp
@@ -42,43 +42,42 @@ TEST(BinaryWriter, basic_interaction)
 
 TEST(BinaryWriter, test_format_marker)
 {
-//    auto root_folder = ".";
-//    auto device_name = "test_device";
-//    uint64_t pulse_id = 5;
-//
-//    BufferBinaryWriter writer(device_name, root_folder);
-//
-//    BufferBinaryFormat frame_data;
-//    frame_data.pulse_id = 1;
-//    frame_data.frame_id = 2;
-//    frame_data.daq_rec = 3;
-//    frame_data.n_recv_packets = 4;
-//
-//    writer.write(5, &frame_data);
-//
-//    auto output_filename =
-//            BufferUtils::get_filename(root_folder, device_name, pulse_id);
-//
-//    auto read_fd = open(output_filename.c_str(), O_RDONLY);
-//    ASSERT_NE(read_fd, -1);
-//
-//    auto file_frame_index = BufferUtils::get_file_frame_index(pulse_id);
-//
-//    BufferBinaryFormat read_data;
-//
-//    // One frame before should be empty.
-//    ::lseek(read_fd, (file_frame_index-1) * sizeof(BufferBinaryFormat), SEEK_SET);
-//    ::read(read_fd, &read_data, sizeof(BufferBinaryFormat));
-//    ASSERT_NE(read_data.FORMAT_MARKER, JF_FORMAT_START_BYTE);
-//
-//    // One frame after should be empty as well.
-//    ::lseek(read_fd, (file_frame_index+1) * sizeof(BufferBinaryFormat), SEEK_SET);
-//    ::read(read_fd, &read_data, sizeof(BufferBinaryFormat));
-//    ASSERT_NE(read_data.FORMAT_MARKER, JF_FORMAT_START_BYTE);
-//
-//    // But this frame should be here.
-//    ::lseek(read_fd, (file_frame_index) * sizeof(BufferBinaryFormat), SEEK_SET);
-//    ::read(read_fd, &read_data, sizeof(BufferBinaryFormat));
-//    ASSERT_EQ(read_data.FORMAT_MARKER, JF_FORMAT_START_BYTE);
+    auto root_folder = ".";
+    auto device_name = "test_device";
+    uint64_t pulse_id = 5;
 
+    BufferBinaryWriter writer(device_name, root_folder);
+
+    BufferBinaryFormat frame_data;
+    frame_data.metadata.pulse_id = 1;
+    frame_data.metadata.frame_index = 2;
+    frame_data.metadata.daq_rec = 3;
+    frame_data.metadata.n_received_packets = 4;
+
+    writer.write(5, &frame_data);
+
+    auto output_filename =
+            BufferUtils::get_filename(root_folder, device_name, pulse_id);
+
+    auto read_fd = open(output_filename.c_str(), O_RDONLY);
+    ASSERT_NE(read_fd, -1);
+
+    auto file_frame_index = BufferUtils::get_file_frame_index(pulse_id);
+
+    BufferBinaryFormat read_data;
+
+    // One frame before should be empty.
+    lseek(read_fd, (file_frame_index-1) * sizeof(BufferBinaryFormat), SEEK_SET);
+    read(read_fd, &read_data, sizeof(BufferBinaryFormat));
+    ASSERT_NE(read_data.FORMAT_MARKER, '\xBE');
+
+    // One frame after should be empty as well.
+    lseek(read_fd, (file_frame_index+1) * sizeof(BufferBinaryFormat), SEEK_SET);
+    read(read_fd, &read_data, sizeof(BufferBinaryFormat));
+    ASSERT_NE(read_data.FORMAT_MARKER, '\xBE');
+
+    // But this frame should be here.
+    lseek(read_fd, (file_frame_index) * sizeof(BufferBinaryFormat), SEEK_SET);
+    read(read_fd, &read_data, sizeof(BufferBinaryFormat));
+    ASSERT_EQ(read_data.FORMAT_MARKER, '\xBE');
 }
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