diff --git a/USER_GUIDE.md b/USER_GUIDE.md
index e4d72b0c..1c523d2a 100644
--- a/USER_GUIDE.md
+++ b/USER_GUIDE.md
@@ -148,6 +148,9 @@ The Settings screen allows you to configure the device's behavior. There are a f
 - **Reader Paragraph Alignment**: Set the alignment of paragraphs; options are "Justified" (default), "Left", "Center", or "Right".
 - **Time to Sleep**: Set the duration of inactivity before the device automatically goes to sleep.
 - **Refresh Frequency**: Set how often the screen does a full refresh while reading to reduce ghosting.
+- **Sunlight Fading Fix**: Configure whether to enable a software-fix for the issue where white X4 models may fade when used in direct sunlight
+  - "OFF" (default) - Disable the fix
+  - "ON" - Enable the fix
 - **OPDS Browser**: Configure OPDS server settings for browsing and downloading books. Set the server URL (for Calibre Content Server, add `/opds` to the end), and optionally configure username and password for servers requiring authentication. Note: Only HTTP Basic authentication is supported. If using Calibre Content Server with authentication enabled, you must set it to use Basic authentication instead of the default Digest authentication.
 - **Check for updates**: Check for firmware updates over WiFi.
 
diff --git a/lib/GfxRenderer/GfxRenderer.cpp b/lib/GfxRenderer/GfxRenderer.cpp
index b5aa7710..5b691589 100644
--- a/lib/GfxRenderer/GfxRenderer.cpp
+++ b/lib/GfxRenderer/GfxRenderer.cpp
@@ -411,7 +411,9 @@ void GfxRenderer::invertScreen() const {
   }
 }
 
-void GfxRenderer::displayBuffer(const HalDisplay::RefreshMode refreshMode) const { display.displayBuffer(refreshMode); }
+void GfxRenderer::displayBuffer(const HalDisplay::RefreshMode refreshMode) const {
+  display.displayBuffer(refreshMode, fadingFix);
+}
 
 std::string GfxRenderer::truncatedText(const int fontId, const char* text, const int maxWidth,
                                        const EpdFontFamily::Style style) const {
@@ -669,7 +671,7 @@ void GfxRenderer::copyGrayscaleLsbBuffers() const { display.copyGrayscaleLsbBuff
 
 void GfxRenderer::copyGrayscaleMsbBuffers() const { display.copyGrayscaleMsbBuffers(display.getFrameBuffer()); }
 
-void GfxRenderer::displayGrayBuffer() const { display.displayGrayBuffer(); }
+void GfxRenderer::displayGrayBuffer() const { display.displayGrayBuffer(fadingFix); }
 
 void GfxRenderer::freeBwBufferChunks() {
   for (auto& bwBufferChunk : bwBufferChunks) {
diff --git a/lib/GfxRenderer/GfxRenderer.h b/lib/GfxRenderer/GfxRenderer.h
index 86ddc8fc..a02a3f8d 100644
--- a/lib/GfxRenderer/GfxRenderer.h
+++ b/lib/GfxRenderer/GfxRenderer.h
@@ -28,6 +28,7 @@ class GfxRenderer {
   HalDisplay& display;
   RenderMode renderMode;
   Orientation orientation;
+  bool fadingFix;
   uint8_t* bwBufferChunks[BW_BUFFER_NUM_CHUNKS] = {nullptr};
   std::map<int, EpdFontFamily> fontMap;
   void renderChar(const EpdFontFamily& fontFamily, uint32_t cp, int* x, const int* y, bool pixelState,
@@ -36,7 +37,8 @@ class GfxRenderer {
   void rotateCoordinates(int x, int y, int* rotatedX, int* rotatedY) const;
 
  public:
-  explicit GfxRenderer(HalDisplay& halDisplay) : display(halDisplay), renderMode(BW), orientation(Portrait) {}
+  explicit GfxRenderer(HalDisplay& halDisplay)
+      : display(halDisplay), renderMode(BW), orientation(Portrait), fadingFix(false) {}
   ~GfxRenderer() { freeBwBufferChunks(); }
 
   static constexpr int VIEWABLE_MARGIN_TOP = 9;
@@ -51,6 +53,9 @@ class GfxRenderer {
   void setOrientation(const Orientation o) { orientation = o; }
   Orientation getOrientation() const { return orientation; }
 
+  // Fading fix control
+  void setFadingFix(const bool enabled) { fadingFix = enabled; }
+
   // Screen ops
   int getScreenWidth() const;
   int getScreenHeight() const;
diff --git a/lib/hal/HalDisplay.cpp b/lib/hal/HalDisplay.cpp
index 6f69d7fc..0fafdbb5 100644
--- a/lib/hal/HalDisplay.cpp
+++ b/lib/hal/HalDisplay.cpp
@@ -28,7 +28,9 @@ EInkDisplay::RefreshMode convertRefreshMode(HalDisplay::RefreshMode mode) {
   }
 }
 
-void HalDisplay::displayBuffer(HalDisplay::RefreshMode mode) { einkDisplay.displayBuffer(convertRefreshMode(mode)); }
+void HalDisplay::displayBuffer(HalDisplay::RefreshMode mode, bool turnOffScreen) {
+  einkDisplay.displayBuffer(convertRefreshMode(mode), turnOffScreen);
+}
 
 void HalDisplay::refreshDisplay(HalDisplay::RefreshMode mode, bool turnOffScreen) {
   einkDisplay.refreshDisplay(convertRefreshMode(mode), turnOffScreen);
@@ -48,4 +50,4 @@ void HalDisplay::copyGrayscaleMsbBuffers(const uint8_t* msbBuffer) { einkDisplay
 
 void HalDisplay::cleanupGrayscaleBuffers(const uint8_t* bwBuffer) { einkDisplay.cleanupGrayscaleBuffers(bwBuffer); }
 
-void HalDisplay::displayGrayBuffer() { einkDisplay.displayGrayBuffer(); }
+void HalDisplay::displayGrayBuffer(bool turnOffScreen) { einkDisplay.displayGrayBuffer(turnOffScreen); }
diff --git a/lib/hal/HalDisplay.h b/lib/hal/HalDisplay.h
index 6eb7156b..238832b0 100644
--- a/lib/hal/HalDisplay.h
+++ b/lib/hal/HalDisplay.h
@@ -31,7 +31,7 @@ class HalDisplay {
   void drawImage(const uint8_t* imageData, uint16_t x, uint16_t y, uint16_t w, uint16_t h,
                  bool fromProgmem = false) const;
 
-  void displayBuffer(RefreshMode mode = RefreshMode::FAST_REFRESH);
+  void displayBuffer(RefreshMode mode = RefreshMode::FAST_REFRESH, bool turnOffScreen = false);
   void refreshDisplay(RefreshMode mode = RefreshMode::FAST_REFRESH, bool turnOffScreen = false);
 
   // Power management
@@ -45,7 +45,7 @@ class HalDisplay {
   void copyGrayscaleMsbBuffers(const uint8_t* msbBuffer);
   void cleanupGrayscaleBuffers(const uint8_t* bwBuffer);
 
-  void displayGrayBuffer();
+  void displayGrayBuffer(bool turnOffScreen = false);
 
  private:
   EInkDisplay einkDisplay;
diff --git a/open-x4-sdk b/open-x4-sdk
index bd4e6707..c8ce3949 160000
--- a/open-x4-sdk
+++ b/open-x4-sdk
@@ -1 +1 @@
-Subproject commit bd4e6707503ab9c97d13ee0d8f8c69e9ff03cd12
+Subproject commit c8ce3949b3368329c290ca1858e65dc3416fc591
diff --git a/src/CrossPointSettings.cpp b/src/CrossPointSettings.cpp
index 232c7c57..f74b0c78 100644
--- a/src/CrossPointSettings.cpp
+++ b/src/CrossPointSettings.cpp
@@ -22,7 +22,7 @@ void readAndValidate(FsFile& file, uint8_t& member, const uint8_t maxValue) {
 namespace {
 constexpr uint8_t SETTINGS_FILE_VERSION = 1;
 // Increment this when adding new persisted settings fields
-constexpr uint8_t SETTINGS_COUNT = 23;
+constexpr uint8_t SETTINGS_COUNT = 24;
 constexpr char SETTINGS_FILE[] = "/.crosspoint/settings.bin";
 }  // namespace
 
@@ -61,6 +61,7 @@ bool CrossPointSettings::saveToFile() const {
   serialization::writeString(outputFile, std::string(opdsPassword));
   serialization::writePod(outputFile, sleepScreenCoverFilter);
   // New fields added at end for backward compatibility
+  serialization::writePod(outputFile, fadingFix);
   outputFile.close();
 
   Serial.printf("[%lu] [CPS] Settings saved to file\n", millis());
@@ -148,6 +149,8 @@ bool CrossPointSettings::loadFromFile() {
     if (++settingsRead >= fileSettingsCount) break;
     readAndValidate(inputFile, sleepScreenCoverFilter, SLEEP_SCREEN_COVER_FILTER_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
+    serialization::readPod(inputFile, fadingFix);
+    if (++settingsRead >= fileSettingsCount) break;
     // New fields added at end for backward compatibility
   } while (false);
 
diff --git a/src/CrossPointSettings.h b/src/CrossPointSettings.h
index c450d348..6ccde287 100644
--- a/src/CrossPointSettings.h
+++ b/src/CrossPointSettings.h
@@ -137,6 +137,8 @@ class CrossPointSettings {
   uint8_t hideBatteryPercentage = HIDE_NEVER;
   // Long-press chapter skip on side buttons
   uint8_t longPressChapterSkip = 1;
+  // Sunlight fading compensation
+  uint8_t fadingFix = 0;
 
   ~CrossPointSettings() = default;
 
diff --git a/src/activities/settings/SettingsActivity.cpp b/src/activities/settings/SettingsActivity.cpp
index 7316db05..a1ca135d 100644
--- a/src/activities/settings/SettingsActivity.cpp
+++ b/src/activities/settings/SettingsActivity.cpp
@@ -11,7 +11,7 @@
 const char* SettingsActivity::categoryNames[categoryCount] = {"Display", "Reader", "Controls", "System"};
 
 namespace {
-constexpr int displaySettingsCount = 6;
+constexpr int displaySettingsCount = 7;
 const SettingInfo displaySettings[displaySettingsCount] = {
     // Should match with SLEEP_SCREEN_MODE
     SettingInfo::Enum("Sleep Screen", &CrossPointSettings::sleepScreen, {"Dark", "Light", "Custom", "Cover", "None"}),
@@ -22,7 +22,9 @@ const SettingInfo displaySettings[displaySettingsCount] = {
                       {"None", "No Progress", "Full w/ Percentage", "Full w/ Progress Bar", "Progress Bar"}),
     SettingInfo::Enum("Hide Battery %", &CrossPointSettings::hideBatteryPercentage, {"Never", "In Reader", "Always"}),
     SettingInfo::Enum("Refresh Frequency", &CrossPointSettings::refreshFrequency,
-                      {"1 page", "5 pages", "10 pages", "15 pages", "30 pages"})};
+                      {"1 page", "5 pages", "10 pages", "15 pages", "30 pages"}),
+    SettingInfo::Enum("Sunlight Fading Fix", &CrossPointSettings::fadingFix, {"OFF", "ON"}),
+};
 
 constexpr int readerSettingsCount = 9;
 const SettingInfo readerSettings[readerSettingsCount] = {
diff --git a/src/main.cpp b/src/main.cpp
index 89c4e13c..ea7a6e6f 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -344,6 +344,8 @@ void loop() {
 
   gpio.update();
 
+  renderer.setFadingFix(SETTINGS.fadingFix);
+
   if (Serial && millis() - lastMemPrint >= 10000) {
     Serial.printf("[%lu] [MEM] Free: %d bytes, Total: %d bytes, Min Free: %d bytes\n", millis(), ESP.getFreeHeap(),
                   ESP.getHeapSize(), ESP.getMinFreeHeap());