diff --git a/src/buffer/out/TextColor.cpp b/src/buffer/out/TextColor.cpp
index af90f9ff85..cf5d35e9ef 100644
--- a/src/buffer/out/TextColor.cpp
+++ b/src/buffer/out/TextColor.cpp
@@ -102,8 +102,8 @@ COLORREF TextColor::GetColor(std::basic_string_view<COLORREF> colorTable,
         if (brighten && _index < 8)
         {
             FAIL_FAST_IF(colorTable.size() < 16);
-            FAIL_FAST_IF((size_t)(_index + 8) > (size_t)(colorTable.size()));
-            return colorTable.at(_index + 8);
+            FAIL_FAST_IF(gsl::narrow_cast<size_t>(_index) + 8 > colorTable.size());
+            return colorTable.at(gsl::narrow_cast<size_t>(_index) + 8);
         }
         else
         {
diff --git a/src/buffer/out/textBuffer.cpp b/src/buffer/out/textBuffer.cpp
index c563fc1e56..3e18662949 100644
--- a/src/buffer/out/textBuffer.cpp
+++ b/src/buffer/out/textBuffer.cpp
@@ -977,9 +977,9 @@ const TextBuffer::TextAndColor TextBuffer::GetTextForClipboard(const bool lineSe
         std::vector<COLORREF> selectionBkAttr;
 
         // preallocate to avoid reallocs
-        selectionText.reserve(highlight.Width() + 2); // + 2 for \r\n if we munged it
-        selectionFgAttr.reserve(highlight.Width() + 2);
-        selectionBkAttr.reserve(highlight.Width() + 2);
+        selectionText.reserve(gsl::narrow<size_t>(highlight.Width()) + 2); // + 2 for \r\n if we munged it
+        selectionFgAttr.reserve(gsl::narrow<size_t>(highlight.Width()) + 2);
+        selectionBkAttr.reserve(gsl::narrow<size_t>(highlight.Width()) + 2);
 
         // copy char data into the string buffer, skipping trailing bytes
         while (it)
@@ -1109,7 +1109,7 @@ std::string TextBuffer::GenHTML(const TextAndColor& rows, const int fontHeightPo
         bool hasWrittenAnyText = false;
         std::optional<COLORREF> fgColor = std::nullopt;
         std::optional<COLORREF> bkColor = std::nullopt;
-        for (UINT row = 0; row < rows.text.size(); row++)
+        for (size_t row = 0; row < rows.text.size(); row++)
         {
             size_t startOffset = 0;
 
@@ -1118,7 +1118,7 @@ std::string TextBuffer::GenHTML(const TextAndColor& rows, const int fontHeightPo
                 htmlBuilder << "<BR>";
             }
 
-            for (UINT col = 0; col < rows.text.at(row).length(); col++)
+            for (size_t col = 0; col < rows.text.at(row).length(); col++)
             {
                 // do not include \r nor \n as they don't have attributes
                 // and are not HTML friendly. For line break use '<BR>' instead.
diff --git a/src/buffer/out/textBufferCellIterator.cpp b/src/buffer/out/textBufferCellIterator.cpp
index 50948ab6bb..b0d09eec2e 100644
--- a/src/buffer/out/textBufferCellIterator.cpp
+++ b/src/buffer/out/textBufferCellIterator.cpp
@@ -212,7 +212,7 @@ void TextBufferCellIterator::_SetPos(const COORD newPos)
 
     if (newPos.X != _pos.X)
     {
-        const ptrdiff_t diff = newPos.X - _pos.X;
+        const ptrdiff_t diff = gsl::narrow_cast<ptrdiff_t>(newPos.X) - gsl::narrow_cast<ptrdiff_t>(_pos.X);
         _attrIter += diff;
     }
 
diff --git a/src/renderer/dx/CustomTextLayout.cpp b/src/renderer/dx/CustomTextLayout.cpp
index 230d1ba56d..f45bc75ba4 100644
--- a/src/renderer/dx/CustomTextLayout.cpp
+++ b/src/renderer/dx/CustomTextLayout.cpp
@@ -39,7 +39,7 @@ CustomTextLayout::CustomTextLayout(IDWriteFactory1* const factory,
     _width{ width }
 {
     // Fetch the locale name out once now from the format
-    _localeName.resize(format->GetLocaleNameLength() + 1); // +1 for null
+    _localeName.resize(gsl::narrow_cast<size_t>(format->GetLocaleNameLength()) + 1); // +1 for null
     THROW_IF_FAILED(format->GetLocaleName(_localeName.data(), gsl::narrow<UINT32>(_localeName.size())));
 
     for (const auto& cluster : clusters)
@@ -306,8 +306,8 @@ CustomTextLayout::CustomTextLayout(IDWriteFactory1* const factory,
 
         // Get the placement of the all the glyphs.
 
-        _glyphAdvances.resize(std::max(static_cast<size_t>(glyphStart + actualGlyphCount), _glyphAdvances.size()));
-        _glyphOffsets.resize(std::max(static_cast<size_t>(glyphStart + actualGlyphCount), _glyphOffsets.size()));
+        _glyphAdvances.resize(std::max(gsl::narrow_cast<size_t>(glyphStart) + gsl::narrow_cast<size_t>(actualGlyphCount), _glyphAdvances.size()));
+        _glyphOffsets.resize(std::max(gsl::narrow_cast<size_t>(glyphStart) + gsl::narrow_cast<size_t>(actualGlyphCount), _glyphOffsets.size()));
 
         const auto fontSizeFormat = _format->GetFontSize();
         const auto fontSize = fontSizeFormat * run.fontScale;
@@ -799,7 +799,7 @@ CustomTextLayout::CustomTextLayout(IDWriteFactory1* const factory,
         RETURN_IF_FAILED(format1->GetFontCollection(&collection));
 
         std::wstring familyName;
-        familyName.resize(format1->GetFontFamilyNameLength() + 1);
+        familyName.resize(gsl::narrow_cast<size_t>(format1->GetFontFamilyNameLength()) + 1);
         RETURN_IF_FAILED(format1->GetFontFamilyName(familyName.data(), gsl::narrow<UINT32>(familyName.size())));
 
         const auto weight = format1->GetFontWeight();
diff --git a/src/types/UiaTextRangeBase.cpp b/src/types/UiaTextRangeBase.cpp
index 3deb97ad49..903751e8f6 100644
--- a/src/types/UiaTextRangeBase.cpp
+++ b/src/types/UiaTextRangeBase.cpp
@@ -569,7 +569,7 @@ IFACEMETHODIMP UiaTextRangeBase::GetText(_In_ int maxLength, _Out_ BSTR* pRetVal
                     if (currentScreenInfoRow == endScreenInfoRow)
                     {
                         // prevent the end from going past the last non-whitespace char in the row
-                        endIndex = std::min(static_cast<size_t>(endColumn + 1), rowRight);
+                        endIndex = std::min(gsl::narrow_cast<size_t>(endColumn) + 1, rowRight);
                     }
 
                     // if startIndex >= endIndex then _start is
@@ -1457,11 +1457,11 @@ std::pair<Endpoint, Endpoint> UiaTextRangeBase::_moveByCharacterForward(IUiaData
 
         // check if we're at the edge of the screen info buffer
         if (currentScreenInfoRow == moveState.LimitingRow &&
-            currentColumn + 1 >= right)
+            gsl::narrow_cast<size_t>(currentColumn) + 1 >= right)
         {
             break;
         }
-        else if (currentColumn + 1 >= right)
+        else if (gsl::narrow_cast<size_t>(currentColumn) + 1 >= right)
         {
             // we're at the edge of a row and need to go to the next one
             currentColumn = moveState.FirstColumnInRow;
@@ -1669,11 +1669,11 @@ UiaTextRangeBase::_moveEndpointByUnitCharacterForward(IUiaData* pData,
 
         // check if we're at the edge of the screen info buffer
         if (currentScreenInfoRow == moveState.LimitingRow &&
-            currentColumn + 1 >= right)
+            gsl::narrow_cast<size_t>(currentColumn) + 1 >= right)
         {
             break;
         }
-        else if (currentColumn + 1 >= right)
+        else if (gsl::narrow_cast<size_t>(currentColumn) + 1 >= right)
         {
             // we're at the edge of a row and need to go to the next one
             currentColumn = moveState.FirstColumnInRow;
diff --git a/src/types/WindowUiaProviderBase.cpp b/src/types/WindowUiaProviderBase.cpp
index 7ff719081b..b98abc2918 100644
--- a/src/types/WindowUiaProviderBase.cpp
+++ b/src/types/WindowUiaProviderBase.cpp
@@ -182,8 +182,13 @@ IFACEMETHODIMP WindowUiaProviderBase::get_BoundingRectangle(_Out_ UiaRect* pRect
 
     pRect->left = rc.left;
     pRect->top = rc.top;
-    pRect->width = rc.right - rc.left;
-    pRect->height = rc.bottom - rc.top;
+
+    LONG longWidth = 0;
+    RETURN_IF_FAILED(LongSub(rc.right, rc.left, &longWidth));
+    pRect->width = longWidth;
+    LONG longHeight = 0;
+    RETURN_IF_FAILED(LongSub(rc.bottom, rc.top, &longHeight));
+    pRect->height = longHeight;
 
     return S_OK;
 }