diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index 28bcdf50c..014deb79c 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -32,9 +32,7 @@
 
 #include <Shiny/Shiny.h>
 
-#if ENABLE_THUMBNAIL_GENERATOR_PNG_TO_GCODE
 #include "miniz_extension.hpp"
-#endif // ENABLE_THUMBNAIL_GENERATOR_PNG_TO_GCODE
 
 #if 0
 // Enable debugging and asserts, even in the release build.
@@ -998,7 +996,6 @@ void GCode::_do_export(Print& print, FILE* file)
         {
             if (data.is_valid())
             {
-#if ENABLE_THUMBNAIL_GENERATOR_PNG_TO_GCODE
                 size_t png_size = 0;
                 void* png_data = tdefl_write_image_to_png_file_in_memory_ex((const void*)data.pixels.data(), data.width, data.height, 4, &png_size, MZ_DEFAULT_LEVEL, 1);
                 if (png_data != nullptr)
@@ -1024,39 +1021,6 @@ void GCode::_do_export(Print& print, FILE* file)
 
                     mz_free(png_data);
                 }
-#else
-                _write_format(file, "\n;\n; thumbnail begin %dx%d\n", data.width, data.height);
-
-                size_t row_size = 4 * data.width;
-                for (int r = (int)data.height - 1; r >= 0; --r)
-                {
-                    std::string encoded;
-                    encoded.resize(boost::beast::detail::base64::encoded_size(row_size));
-                    encoded.resize(boost::beast::detail::base64::encode((void*)&encoded[0], (const void*)(data.pixels.data() + r * row_size), row_size));
-
-                    unsigned int row_count = 0;
-                    while (encoded.size() > max_row_length)
-                    {
-                        if (row_count == 0)
-                            _write_format(file, "; %s\n", encoded.substr(0, max_row_length).c_str());
-                        else
-                            _write_format(file, ";>%s\n", encoded.substr(0, max_row_length).c_str());
-
-                        encoded = encoded.substr(max_row_length);
-                        ++row_count;
-                    }
-
-                    if (encoded.size() > 0)
-                    {
-                        if (row_count == 0)
-                            _write_format(file, "; %s\n", encoded.c_str());
-                        else
-                            _write_format(file, ";>%s\n", encoded.c_str());
-                    }
-                }
-
-                _write(file, "; thumbnail end\n;\n");
-#endif // ENABLE_THUMBNAIL_GENERATOR_PNG_TO_GCODE
             }
             print.throw_if_canceled();
         }
diff --git a/src/libslic3r/Technologies.hpp b/src/libslic3r/Technologies.hpp
index f8db1b7b3..7a6a682b1 100644
--- a/src/libslic3r/Technologies.hpp
+++ b/src/libslic3r/Technologies.hpp
@@ -40,7 +40,6 @@
 // Enable thumbnail generator
 #define ENABLE_THUMBNAIL_GENERATOR (1 && ENABLE_2_2_0_ALPHA1)
 #define ENABLE_THUMBNAIL_GENERATOR_DEBUG (0 && ENABLE_THUMBNAIL_GENERATOR)
-#define ENABLE_THUMBNAIL_GENERATOR_PNG_TO_GCODE (1 && ENABLE_THUMBNAIL_GENERATOR)
 
 // Enable adaptive layer height profile
 #define ENABLE_ADAPTIVE_LAYER_HEIGHT_PROFILE (1 && ENABLE_2_2_0_ALPHA1)
diff --git a/src/slic3r/GUI/GUI_App.cpp b/src/slic3r/GUI/GUI_App.cpp
index 7d37baa66..a74c6b0c0 100644
--- a/src/slic3r/GUI/GUI_App.cpp
+++ b/src/slic3r/GUI/GUI_App.cpp
@@ -1126,7 +1126,6 @@ void GUI_App::gcode_thumbnails_debug()
                 }
                 else if (reading_image && boost::starts_with(gcode_line, END_MASK))
                 {
-#if ENABLE_THUMBNAIL_GENERATOR_PNG_TO_GCODE
                     std::string out_filename = out_path + std::to_string(width) + "x" + std::to_string(height) + ".png";
                     boost::nowide::ofstream out_file(out_filename.c_str(), std::ios::binary);
                     if (out_file.good())
@@ -1138,46 +1137,6 @@ void GUI_App::gcode_thumbnails_debug()
                         out_file.write(decoded.c_str(), decoded.size());
                         out_file.close();
                     }
-#else
-                    if (!row.empty())
-                    {
-                        rows.push_back(row);
-                        row.clear();
-                    }
-
-                    if ((unsigned int)rows.size() == height)
-                    {
-                        std::vector<unsigned char> thumbnail(4 * width * height, 0);
-                        for (unsigned int r = 0; r < (unsigned int)rows.size(); ++r)
-                        {
-                            std::string decoded_row;
-                            decoded_row.resize(boost::beast::detail::base64::decoded_size(rows[r].size()));
-                            decoded_row.resize(boost::beast::detail::base64::decode((void*)&decoded_row[0], rows[r].data(), rows[r].size()).first);
-
-                            if ((unsigned int)decoded_row.size() == width * 4)
-                            {
-                                void* image_ptr = (void*)(thumbnail.data() + r * width * 4);
-                                ::memcpy(image_ptr, (const void*)decoded_row.c_str(), width * 4);
-                            }
-                        }
-
-                        wxImage image(width, height);
-                        image.InitAlpha();
-
-                        for (unsigned int r = 0; r < height; ++r)
-                        {
-                            unsigned int rr = r * width;
-                            for (unsigned int c = 0; c < width; ++c)
-                            {
-                                unsigned char* px = thumbnail.data() + 4 * (rr + c);
-                                image.SetRGB((int)c, (int)r, px[0], px[1], px[2]);
-                                image.SetAlpha((int)c, (int)r, px[3]);
-                            }
-                        }
-
-                        image.SaveFile(out_path + std::to_string(width) + "x" + std::to_string(height) + ".png", wxBITMAP_TYPE_PNG);
-                    }
-#endif // ENABLE_THUMBNAIL_GENERATOR_PNG_TO_GCODE
 
                     reading_image = false;
                     width = 0;
@@ -1185,17 +1144,7 @@ void GUI_App::gcode_thumbnails_debug()
                     rows.clear();
                 }
                 else if (reading_image)
-                {
-#if !ENABLE_THUMBNAIL_GENERATOR_PNG_TO_GCODE
-                    if (!row.empty() && (gcode_line[1] == ' '))
-                    {
-                        rows.push_back(row);
-                        row.clear();
-                    }
-#endif // !ENABLE_THUMBNAIL_GENERATOR_PNG_TO_GCODE
-
                     row += gcode_line.substr(2);
-                }
             }
         }