diff --git a/lib/Epub/Epub/converters/DitherUtils.h b/lib/Epub/Epub/converters/DitherUtils.h
index 8107f2eb..19de605c 100644
--- a/lib/Epub/Epub/converters/DitherUtils.h
+++ b/lib/Epub/Epub/converters/DitherUtils.h
@@ -32,6 +32,7 @@ inline uint8_t applyBayerDither4Level(uint8_t gray, int x, int y) {
   return quantizeGray4Level((uint8_t)adjusted);
 }
 
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
 class DiffusedBayerDitherer {
  public:
   explicit DiffusedBayerDitherer(int width) : width(width) {
@@ -85,3 +86,4 @@ class DiffusedBayerDitherer {
   int16_t* errorCurRow;
   int16_t* errorNextRow;
 };
+#endif
diff --git a/lib/Epub/Epub/converters/ImageToFramebufferDecoder.h b/lib/Epub/Epub/converters/ImageToFramebufferDecoder.h
index 0bdc4a86..c938785d 100644
--- a/lib/Epub/Epub/converters/ImageToFramebufferDecoder.h
+++ b/lib/Epub/Epub/converters/ImageToFramebufferDecoder.h
@@ -13,12 +13,15 @@ struct ImageDimensions {
 
 enum class ImageDitherMode : uint8_t {
   Bayer = 0,
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
   Atkinson = 1,
   DiffusedBayer = 2,
+#endif
   COUNT,
 };
 
 inline ImageDitherMode imageDitherModeFromSetting(uint8_t value) {
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
   switch (static_cast<ImageDitherMode>(value)) {
     case ImageDitherMode::Bayer:
     case ImageDitherMode::Atkinson:
@@ -28,14 +31,20 @@ inline ImageDitherMode imageDitherModeFromSetting(uint8_t value) {
     default:
       return ImageDitherMode::Bayer;
   }
+#else
+  (void)value;
+  return ImageDitherMode::Bayer;
+#endif
 }
 
 inline const char* getImageDitherCacheSuffix(ImageDitherMode mode) {
   switch (mode) {
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
     case ImageDitherMode::Atkinson:
       return ".atkinson";
     case ImageDitherMode::DiffusedBayer:
       return ".diffused-bayer";
+#endif
     case ImageDitherMode::Bayer:
     case ImageDitherMode::COUNT:
     default:
diff --git a/lib/Epub/Epub/converters/JpegToFramebufferConverter.cpp b/lib/Epub/Epub/converters/JpegToFramebufferConverter.cpp
index f76613a6..e8394f84 100644
--- a/lib/Epub/Epub/converters/JpegToFramebufferConverter.cpp
+++ b/lib/Epub/Epub/converters/JpegToFramebufferConverter.cpp
@@ -1,6 +1,8 @@
 #include "JpegToFramebufferConverter.h"
 
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
 #include <BitmapHelpers.h>
+#endif
 #include <FsHelpers.h>
 #include <GfxRenderer.h>
 #include <HalStorage.h>
@@ -40,9 +42,11 @@ struct JpegContext {
   PixelCache cache;
   bool caching;
 
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
   int currentDitherRow;
   AtkinsonDitherer* atkinsonDitherer;
   DiffusedBayerDitherer* diffusedBayerDitherer;
+#endif
 
   JpegContext()
       : renderer(nullptr),
@@ -55,17 +59,25 @@ struct JpegContext {
         dstHeight(0),
         fineScaleFP(1 << 16),
         invScaleFP(1 << 16),
-        caching(false),
+        caching(false)
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
+        ,
         currentDitherRow(-1),
         atkinsonDitherer(nullptr),
-        diffusedBayerDitherer(nullptr) {}
+        diffusedBayerDitherer(nullptr)
+#endif
+  {
+  }
 
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
   ~JpegContext() {
     delete atkinsonDitherer;
     delete diffusedBayerDitherer;
   }
+#endif
 };
 
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
 void prepareDitherRow(JpegContext& ctx, int dstY) {
   if (!ctx.config || !ctx.config->useDithering) return;
 
@@ -107,6 +119,13 @@ uint8_t ditherGray(JpegContext& ctx, uint8_t gray, int localX, int outX, int out
 
   return applyBayerDither4Level(gray, outX, outY);
 }
+#else
+uint8_t ditherGray(JpegContext& ctx, uint8_t gray, int localX, int outX, int outY) {
+  (void)ctx;
+  (void)localX;
+  return applyBayerDither4Level(gray, outX, outY);
+}
+#endif
 
 // File I/O callbacks use pFile->fHandle to access the FsFile*,
 // avoiding the need for global file state.
@@ -235,7 +254,9 @@ int jpegDrawCallback(JPEGDRAW* pDraw) {
   if (fineScaleFP == FP_ONE) {
     for (int dstY = dstYStart; dstY < dstYEnd; dstY++) {
       const int outY = cfgY + dstY;
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
       prepareDitherRow(*ctx, dstY);
+#endif
       pw.beginRow(outY);
       if (caching) cw.beginRow(outY, ctx->config->y);
       const uint8_t* row = &pixels[(dstY - blockY) * stride];
@@ -264,7 +285,9 @@ int jpegDrawCallback(JPEGDRAW* pDraw) {
 
     for (int dstY = dstYStart; dstY < dstYEnd; dstY++) {
       const int outY = cfgY + dstY;
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
       prepareDitherRow(*ctx, dstY);
+#endif
       pw.beginRow(outY);
       if (caching) cw.beginRow(outY, ctx->config->y);
       const int32_t srcFyFP = dstY * invScaleFP;
@@ -344,7 +367,9 @@ int jpegDrawCallback(JPEGDRAW* pDraw) {
   // === Nearest-neighbor (downscale: fineScale < 1.0) ===
   for (int dstY = dstYStart; dstY < dstYEnd; dstY++) {
     const int outY = cfgY + dstY;
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
     prepareDitherRow(*ctx, dstY);
+#endif
     pw.beginRow(outY);
     if (caching) cw.beginRow(outY, ctx->config->y);
     const int32_t srcFyFP = dstY * invScaleFP;
@@ -507,6 +532,7 @@ bool JpegToFramebufferConverter::decodeToFramebuffer(const std::string& imagePat
   }
 
   if (config.useDithering) {
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
     switch (config.ditherMode) {
       case ImageDitherMode::Atkinson:
         ctx.atkinsonDitherer = new (std::nothrow) AtkinsonDitherer(destWidth);
@@ -525,6 +551,7 @@ bool JpegToFramebufferConverter::decodeToFramebuffer(const std::string& imagePat
       default:
         break;
     }
+#endif
   }
 
   unsigned long decodeStart = millis();
diff --git a/lib/Epub/Epub/converters/PngToFramebufferConverter.cpp b/lib/Epub/Epub/converters/PngToFramebufferConverter.cpp
index 7ef7826a..e9aa0aad 100644
--- a/lib/Epub/Epub/converters/PngToFramebufferConverter.cpp
+++ b/lib/Epub/Epub/converters/PngToFramebufferConverter.cpp
@@ -1,6 +1,8 @@
 #include "PngToFramebufferConverter.h"
 
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
 #include <BitmapHelpers.h>
+#endif
 #include <FsHelpers.h>
 #include <GfxRenderer.h>
 #include <HalStorage.h>
@@ -37,9 +39,11 @@ struct PngContext {
   bool caching;
 
   uint8_t* grayLineBuffer;
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
   int currentDitherRow;
   AtkinsonDitherer* atkinsonDitherer;
   DiffusedBayerDitherer* diffusedBayerDitherer;
+#endif
 
   PngContext()
       : renderer(nullptr),
@@ -53,17 +57,25 @@ struct PngContext {
         dstHeight(0),
         lastDstY(-1),
         caching(false),
-        grayLineBuffer(nullptr),
+        grayLineBuffer(nullptr)
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
+        ,
         currentDitherRow(-1),
         atkinsonDitherer(nullptr),
-        diffusedBayerDitherer(nullptr) {}
+        diffusedBayerDitherer(nullptr)
+#endif
+  {
+  }
 
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
   ~PngContext() {
     delete atkinsonDitherer;
     delete diffusedBayerDitherer;
   }
+#endif
 };
 
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
 void prepareDitherRow(PngContext& ctx, int dstY) {
   if (!ctx.config || !ctx.config->useDithering) return;
 
@@ -105,6 +117,13 @@ uint8_t ditherGray(PngContext& ctx, uint8_t gray, int localX, int outX, int outY
 
   return applyBayerDither4Level(gray, outX, outY);
 }
+#else
+uint8_t ditherGray(PngContext& ctx, uint8_t gray, int localX, int outX, int outY) {
+  (void)ctx;
+  (void)localX;
+  return applyBayerDither4Level(gray, outX, outY);
+}
+#endif
 
 // File I/O callbacks use pFile->fHandle to access the FsFile*,
 // avoiding the need for global file state.
@@ -272,7 +291,9 @@ int pngDrawCallback(PNGDRAW* pDraw) {
     cw.beginRow(outY, ctx->config->y);
   }
 
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
   prepareDitherRow(*ctx, dstY);
+#endif
 
   int srcX = 0;
   int error = 0;
@@ -435,6 +456,7 @@ bool PngToFramebufferConverter::decodeToFramebuffer(const std::string& imagePath
   }
 
   if (config.useDithering) {
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
     switch (config.ditherMode) {
       case ImageDitherMode::Atkinson:
         ctx.atkinsonDitherer = new (std::nothrow) AtkinsonDitherer(ctx.dstWidth);
@@ -453,6 +475,7 @@ bool PngToFramebufferConverter::decodeToFramebuffer(const std::string& imagePath
       default:
         break;
     }
+#endif
   }
 
   unsigned long decodeStart = millis();
diff --git a/src/CrossPointSettings.h b/src/CrossPointSettings.h
index 7d1a3484..7c6ea750 100644
--- a/src/CrossPointSettings.h
+++ b/src/CrossPointSettings.h
@@ -137,12 +137,16 @@ class CrossPointSettings {
 
   // Image rendering in EPUB reader
   enum IMAGE_RENDERING { IMAGES_DISPLAY = 0, IMAGES_PLACEHOLDER = 1, IMAGES_SUPPRESS = 2, IMAGE_RENDERING_COUNT };
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
   enum IMAGE_DITHERING {
     IMAGE_DITHER_BAYER = 0,
     IMAGE_DITHER_ATKINSON = 1,
     IMAGE_DITHER_DIFFUSED_BAYER = 2,
     IMAGE_DITHERING_COUNT
   };
+#else
+  enum IMAGE_DITHERING { IMAGE_DITHER_BAYER = 0, IMAGE_DITHERING_COUNT };
+#endif
 
   // Timezone options (POSIX TZ rules for DST support)
   enum TIMEZONE {
diff --git a/src/SettingsList.h b/src/SettingsList.h
index a891b45e..8bfa98e3 100644
--- a/src/SettingsList.h
+++ b/src/SettingsList.h
@@ -69,10 +69,12 @@ inline const std::vector<SettingInfo>& getSettingsList() {
       SettingInfo::Enum(StrId::STR_IMAGES, &CrossPointSettings::imageRendering,
                         {StrId::STR_IMAGES_DISPLAY, StrId::STR_IMAGES_PLACEHOLDER, StrId::STR_IMAGES_SUPPRESS},
                         "imageRendering", StrId::STR_CAT_READER),
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
       SettingInfo::Enum(
           StrId::STR_IMAGE_DITHERING, &CrossPointSettings::imageDithering,
           {StrId::STR_IMAGE_DITHER_BAYER, StrId::STR_IMAGE_DITHER_ATKINSON, StrId::STR_IMAGE_DITHER_DIFFUSED_BAYER},
           "imageDithering", StrId::STR_CAT_READER),
+#endif
       SettingInfo::Toggle(StrId::STR_CREATE_FALLBACK_FOR_INVALID_TOC, &CrossPointSettings::syntheticTocFallback,
                           "syntheticTocFallback", StrId::STR_CAT_READER),
       // --- Controls ---
diff --git a/src/activities/util/BmpViewerActivity.cpp b/src/activities/util/BmpViewerActivity.cpp
index f8bd8a6c..b0126c24 100644
--- a/src/activities/util/BmpViewerActivity.cpp
+++ b/src/activities/util/BmpViewerActivity.cpp
@@ -20,7 +20,9 @@ constexpr const char* SLEEP_BMP_PATH = "/sleep.bmp";
 constexpr const char* SLEEP_BMP_TMP_PATH = "/sleep.bmp.tmp";
 constexpr const char* SLEEP_BMP_BACKUP_PATH = "/sleep.bmp.bak";
 
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
 uint8_t normalizeImageDitherModeValue(uint8_t mode) { return static_cast<uint8_t>(imageDitherModeFromSetting(mode)); }
+#endif
 
 bool isBmpFile(const std::string& path) { return FsHelpers::hasBmpExtension(path); }
 
@@ -87,8 +89,15 @@ bool replaceSleepBmpFromTemp() {
 
 BmpViewerActivity::BmpViewerActivity(GfxRenderer& renderer, MappedInputManager& mappedInput, std::string path)
     : Activity("BmpViewer", renderer, mappedInput),
-      filePath(std::move(path)),
-      imageDitherMode(normalizeImageDitherModeValue(SETTINGS.imageDithering)) {}
+      filePath(std::move(path))
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
+      ,
+      imageDitherMode(normalizeImageDitherModeValue(SETTINGS.imageDithering)) {
+}
+#else
+{
+}
+#endif
 
 bool BmpViewerActivity::renderCurrentImage(const bool showControls) {
   return isBmpFile(filePath) ? renderBmpImage(showControls) : renderDecodedImage(showControls);
@@ -139,8 +148,12 @@ bool BmpViewerActivity::renderBmpImage(const bool showControls) {
   renderer.clearScreen();
   renderer.drawBitmap(bitmap, x, y, pageWidth, pageHeight, 0, 0);
   if (showControls) {
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
     const auto labels =
         mappedInput.mapLabels(tr(STR_BACK), "", I18N.get(getCurrentDitherModeLabel()), tr(STR_SET_SLEEP_SCREEN));
+#else
+    const auto labels = mappedInput.mapLabels(tr(STR_BACK), "", "", tr(STR_SET_SLEEP_SCREEN));
+#endif
     GUI.drawButtonHints(renderer, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
   }
   renderer.displayBuffer(HalDisplay::HALF_REFRESH);
@@ -179,21 +192,30 @@ bool BmpViewerActivity::renderDecodedImage(const bool showControls) {
   config.useExactDimensions = true;
   config.useGrayscale = true;
   config.useDithering = true;
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
   config.ditherMode = imageDitherModeFromSetting(imageDitherMode);
+#else
+  config.ditherMode = ImageDitherMode::Bayer;
+#endif
 
   if (!decoder->decodeToFramebuffer(filePath, renderer, config)) {
     return false;
   }
 
   if (showControls) {
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
     const auto labels =
         mappedInput.mapLabels(tr(STR_BACK), "", I18N.get(getCurrentDitherModeLabel()), tr(STR_SET_SLEEP_SCREEN));
+#else
+    const auto labels = mappedInput.mapLabels(tr(STR_BACK), "", "", tr(STR_SET_SLEEP_SCREEN));
+#endif
     GUI.drawButtonHints(renderer, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
   }
   renderer.displayBuffer(HalDisplay::HALF_REFRESH);
   return true;
 }
 
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
 StrId BmpViewerActivity::getCurrentDitherModeLabel() const {
   switch (imageDitherModeFromSetting(imageDitherMode)) {
     case ImageDitherMode::Atkinson:
@@ -216,6 +238,7 @@ void BmpViewerActivity::cycleDitherMode() {
     renderError("Could not render image");
   }
 }
+#endif
 
 void BmpViewerActivity::renderError(const char* message) {
   const auto pageHeight = renderer.getScreenHeight();
@@ -278,10 +301,12 @@ void BmpViewerActivity::loop() {
     return;
   }
 
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
   if (mappedInput.wasReleased(MappedInputManager::Button::Left)) {
     cycleDitherMode();
     return;
   }
+#endif
 
   // Next/Right button: set this image as the sleep screen
   if (mappedInput.wasReleased(MappedInputManager::Button::Right)) {
diff --git a/src/activities/util/BmpViewerActivity.h b/src/activities/util/BmpViewerActivity.h
index 5fc1f692..4e88166a 100644
--- a/src/activities/util/BmpViewerActivity.h
+++ b/src/activities/util/BmpViewerActivity.h
@@ -19,12 +19,16 @@ class BmpViewerActivity final : public Activity {
 
  private:
   std::string filePath;
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
   uint8_t imageDitherMode;
+#endif
   bool renderCurrentImage(bool showControls = true);
   bool renderBmpImage(bool showControls = true);
   bool renderDecodedImage(bool showControls = true);
+#ifdef ENABLE_IMAGE_DITHERING_EXTENSION
   void cycleDitherMode();
   StrId getCurrentDitherModeLabel() const;
+#endif
   void renderError(const char* message);
   void setAsSleepScreen();
 };