diff --git a/lib/Epub/Epub/Page.cpp b/lib/Epub/Epub/Page.cpp
index 65ce5698..92839eb7 100644
--- a/lib/Epub/Epub/Page.cpp
+++ b/lib/Epub/Epub/Page.cpp
@@ -32,7 +32,7 @@ void Page::render(GfxRenderer& renderer, const int fontId, const int xOffset, co
 }
 
 bool Page::serialize(FsFile& file) const {
-  const uint32_t count = elements.size();
+  const uint16_t count = elements.size();
   serialization::writePod(file, count);
 
   for (const auto& el : elements) {
@@ -49,10 +49,10 @@ bool Page::serialize(FsFile& file) const {
 std::unique_ptr<Page> Page::deserialize(FsFile& file) {
   auto page = std::unique_ptr<Page>(new Page());
 
-  uint32_t count;
+  uint16_t count;
   serialization::readPod(file, count);
 
-  for (uint32_t i = 0; i < count; i++) {
+  for (uint16_t i = 0; i < count; i++) {
     uint8_t tag;
     serialization::readPod(file, tag);
 
diff --git a/lib/Epub/Epub/ParsedText.cpp b/lib/Epub/Epub/ParsedText.cpp
index 91834203..f9c0326f 100644
--- a/lib/Epub/Epub/ParsedText.cpp
+++ b/lib/Epub/Epub/ParsedText.cpp
@@ -18,7 +18,7 @@ void ParsedText::addWord(std::string word, const EpdFontFamily::Style fontStyle)
 }
 
 // Consumes data to minimize memory usage
-void ParsedText::layoutAndExtractLines(const GfxRenderer& renderer, const int fontId, const int viewportWidth,
+void ParsedText::layoutAndExtractLines(const GfxRenderer& renderer, const int fontId, const uint16_t viewportWidth,
                                        const std::function<void(std::shared_ptr<TextBlock>)>& processLine,
                                        const bool includeLastLine) {
   if (words.empty()) {
diff --git a/lib/Epub/Epub/ParsedText.h b/lib/Epub/Epub/ParsedText.h
index 109677cf..4b851a94 100644
--- a/lib/Epub/Epub/ParsedText.h
+++ b/lib/Epub/Epub/ParsedText.h
@@ -34,7 +34,7 @@ class ParsedText {
   TextBlock::Style getStyle() const { return style; }
   size_t size() const { return words.size(); }
   bool isEmpty() const { return words.empty(); }
-  void layoutAndExtractLines(const GfxRenderer& renderer, int fontId, int viewportWidth,
+  void layoutAndExtractLines(const GfxRenderer& renderer, int fontId, uint16_t viewportWidth,
                              const std::function<void(std::shared_ptr<TextBlock>)>& processLine,
                              bool includeLastLine = true);
 };
diff --git a/lib/Epub/Epub/Section.cpp b/lib/Epub/Epub/Section.cpp
index ef1e140b..1f99f018 100644
--- a/lib/Epub/Epub/Section.cpp
+++ b/lib/Epub/Epub/Section.cpp
@@ -8,8 +8,8 @@
 
 namespace {
 constexpr uint8_t SECTION_FILE_VERSION = 8;
-constexpr uint32_t HEADER_SIZE = sizeof(uint8_t) + sizeof(int) + sizeof(float) + sizeof(bool) + sizeof(int) +
-                                 sizeof(int) + sizeof(int) + sizeof(uint32_t);
+constexpr uint32_t HEADER_SIZE = sizeof(uint8_t) + sizeof(int) + sizeof(float) + sizeof(bool) + sizeof(uint16_t) +
+                                 sizeof(uint16_t) + sizeof(uint16_t) + sizeof(uint32_t);
 }  // namespace
 
 uint32_t Section::onPageComplete(std::unique_ptr<Page> page) {
@@ -30,7 +30,7 @@ uint32_t Section::onPageComplete(std::unique_ptr<Page> page) {
 }
 
 void Section::writeSectionFileHeader(const int fontId, const float lineCompression, const bool extraParagraphSpacing,
-                                     const int viewportWidth, const int viewportHeight) {
+                                     const uint16_t viewportWidth, const uint16_t viewportHeight) {
   if (!file) {
     Serial.printf("[%lu] [SCT] File not open for writing header\n", millis());
     return;
@@ -50,7 +50,7 @@ void Section::writeSectionFileHeader(const int fontId, const float lineCompressi
 }
 
 bool Section::loadSectionFile(const int fontId, const float lineCompression, const bool extraParagraphSpacing,
-                              const int viewportWidth, const int viewportHeight) {
+                              const uint16_t viewportWidth, const uint16_t viewportHeight) {
   if (!SdMan.openFileForRead("SCT", filePath, file)) {
     return false;
   }
@@ -66,7 +66,8 @@ bool Section::loadSectionFile(const int fontId, const float lineCompression, con
       return false;
     }
 
-    int fileFontId, fileViewportWidth, fileViewportHeight;
+    int fileFontId;
+    uint16_t fileViewportWidth, fileViewportHeight;
     float fileLineCompression;
     bool fileExtraParagraphSpacing;
     serialization::readPod(file, fileFontId);
@@ -108,7 +109,7 @@ bool Section::clearCache() const {
 }
 
 bool Section::createSectionFile(const int fontId, const float lineCompression, const bool extraParagraphSpacing,
-                                const int viewportWidth, const int viewportHeight,
+                                const uint16_t viewportWidth, const uint16_t viewportHeight,
                                 const std::function<void()>& progressSetupFn,
                                 const std::function<void(int)>& progressFn) {
   constexpr uint32_t MIN_SIZE_FOR_PROGRESS = 50 * 1024;  // 50KB
diff --git a/lib/Epub/Epub/Section.h b/lib/Epub/Epub/Section.h
index bc2efabc..55244d0e 100644
--- a/lib/Epub/Epub/Section.h
+++ b/lib/Epub/Epub/Section.h
@@ -14,12 +14,12 @@ class Section {
   std::string filePath;
   FsFile file;
 
-  void writeSectionFileHeader(int fontId, float lineCompression, bool extraParagraphSpacing, int viewportWidth,
-                              int viewportHeight);
+  void writeSectionFileHeader(int fontId, float lineCompression, bool extraParagraphSpacing, uint16_t viewportWidth,
+                              uint16_t viewportHeight);
   uint32_t onPageComplete(std::unique_ptr<Page> page);
 
  public:
-  int pageCount = 0;
+  uint16_t pageCount = 0;
   int currentPage = 0;
 
   explicit Section(const std::shared_ptr<Epub>& epub, const int spineIndex, GfxRenderer& renderer)
@@ -28,11 +28,11 @@ class Section {
         renderer(renderer),
         filePath(epub->getCachePath() + "/sections/" + std::to_string(spineIndex) + ".bin") {}
   ~Section() = default;
-  bool loadSectionFile(int fontId, float lineCompression, bool extraParagraphSpacing, int viewportWidth,
-                       int viewportHeight);
+  bool loadSectionFile(int fontId, float lineCompression, bool extraParagraphSpacing, uint16_t viewportWidth,
+                       uint16_t viewportHeight);
   bool clearCache() const;
-  bool createSectionFile(int fontId, float lineCompression, bool extraParagraphSpacing, int viewportWidth,
-                         int viewportHeight, const std::function<void()>& progressSetupFn = nullptr,
+  bool createSectionFile(int fontId, float lineCompression, bool extraParagraphSpacing, uint16_t viewportWidth,
+                         uint16_t viewportHeight, const std::function<void()>& progressSetupFn = nullptr,
                          const std::function<void(int)>& progressFn = nullptr);
   std::unique_ptr<Page> loadPageFromSectionFile();
 };
diff --git a/lib/Epub/Epub/blocks/TextBlock.cpp b/lib/Epub/Epub/blocks/TextBlock.cpp
index b1fe078f..2a15aef0 100644
--- a/lib/Epub/Epub/blocks/TextBlock.cpp
+++ b/lib/Epub/Epub/blocks/TextBlock.cpp
@@ -32,7 +32,7 @@ bool TextBlock::serialize(FsFile& file) const {
   }
 
   // Word data
-  serialization::writePod(file, static_cast<uint32_t>(words.size()));
+  serialization::writePod(file, static_cast<uint16_t>(words.size()));
   for (const auto& w : words) serialization::writeString(file, w);
   for (auto x : wordXpos) serialization::writePod(file, x);
   for (auto s : wordStyles) serialization::writePod(file, s);
@@ -44,7 +44,7 @@ bool TextBlock::serialize(FsFile& file) const {
 }
 
 std::unique_ptr<TextBlock> TextBlock::deserialize(FsFile& file) {
-  uint32_t wc;
+  uint16_t wc;
   std::list<std::string> words;
   std::list<uint16_t> wordXpos;
   std::list<EpdFontFamily::Style> wordStyles;
diff --git a/lib/Epub/Epub/blocks/TextBlock.h b/lib/Epub/Epub/blocks/TextBlock.h
index ea2314a6..415a18f3 100644
--- a/lib/Epub/Epub/blocks/TextBlock.h
+++ b/lib/Epub/Epub/blocks/TextBlock.h
@@ -8,7 +8,7 @@
 
 #include "Block.h"
 
-// represents a block of words in the html document
+// Represents a line of text on a page
 class TextBlock final : public Block {
  public:
   enum Style : uint8_t {
diff --git a/lib/Epub/Epub/parsers/ChapterHtmlSlimParser.h b/lib/Epub/Epub/parsers/ChapterHtmlSlimParser.h
index 1956ce0c..795c2c33 100644
--- a/lib/Epub/Epub/parsers/ChapterHtmlSlimParser.h
+++ b/lib/Epub/Epub/parsers/ChapterHtmlSlimParser.h
@@ -33,8 +33,8 @@ class ChapterHtmlSlimParser {
   int fontId;
   float lineCompression;
   bool extraParagraphSpacing;
-  int viewportWidth;
-  int viewportHeight;
+  uint16_t viewportWidth;
+  uint16_t viewportHeight;
 
   void startNewTextBlock(TextBlock::Style style);
   void makePages();
@@ -45,8 +45,8 @@ class ChapterHtmlSlimParser {
 
  public:
   explicit ChapterHtmlSlimParser(const std::string& filepath, GfxRenderer& renderer, const int fontId,
-                                 const float lineCompression, const bool extraParagraphSpacing, const int viewportWidth,
-                                 const int viewportHeight,
+                                 const float lineCompression, const bool extraParagraphSpacing,
+                                 const uint16_t viewportWidth, const uint16_t viewportHeight,
                                  const std::function<void(std::unique_ptr<Page>)>& completePageFn,
                                  const std::function<void(int)>& progressFn = nullptr)
       : filepath(filepath),
diff --git a/src/activities/reader/EpubReaderActivity.cpp b/src/activities/reader/EpubReaderActivity.cpp
index d1025c8c..fae5d241 100644
--- a/src/activities/reader/EpubReaderActivity.cpp
+++ b/src/activities/reader/EpubReaderActivity.cpp
@@ -263,8 +263,8 @@ void EpubReaderActivity::renderScreen() {
     Serial.printf("[%lu] [ERS] Loading file: %s, index: %d\n", millis(), filepath.c_str(), currentSpineIndex);
     section = std::unique_ptr<Section>(new Section(epub, currentSpineIndex, renderer));
 
-    const auto viewportWidth = renderer.getScreenWidth() - orientedMarginLeft - orientedMarginRight;
-    const auto viewportHeight = renderer.getScreenHeight() - orientedMarginTop - orientedMarginBottom;
+    const uint16_t viewportWidth = renderer.getScreenWidth() - orientedMarginLeft - orientedMarginRight;
+    const uint16_t viewportHeight = renderer.getScreenHeight() - orientedMarginTop - orientedMarginBottom;
 
     if (!section->loadSectionFile(SETTINGS.getReaderFontId(), SETTINGS.getReaderLineCompression(),
                                   SETTINGS.extraParagraphSpacing, viewportWidth, viewportHeight)) {