diff --git a/qrenderdoc/Code/QRDUtils.h b/qrenderdoc/Code/QRDUtils.h
index 3c3b2c2b2..77801afbb 100644
--- a/qrenderdoc/Code/QRDUtils.h
+++ b/qrenderdoc/Code/QRDUtils.h
@@ -27,6 +27,7 @@
 #include <QCheckBox>
 #include <QCoreApplication>
 #include <QDebug>
+#include <QDoubleSpinBox>
 #include <QFileDialog>
 #include <QMessageBox>
 #include <QProcess>
@@ -575,6 +576,42 @@ private:
   QAbstractItemView *m_widget;
 };
 
+// helper functions for using a double spinbox for 64-bit integers. We do this because it's
+// infeasible in Qt to actually derive and create a real 64-bit integer spinbox because critical
+// functionality depends on deriving QAbstractSpinBoxPrivate which is unavailable. So instead we use
+// a QDoubleSpinBox and restrict ourselves to the 53 bits of mantissa. This struct only has inline
+// helpers so we can cast a QDoubleSpinBox to one of these and use it as-is.
+class RDSpinBox64 : public QDoubleSpinBox
+{
+private:
+  static const qlonglong mask = (1ULL << 53U) - 1;
+
+public:
+  void configure() { QDoubleSpinBox::setDecimals(0); }
+  void setSingleStep(qlonglong val) { QDoubleSpinBox::setSingleStep(makeValue(val)); }
+  void setMinimum(qlonglong min) { QDoubleSpinBox::setMinimum(makeValue(min)); }
+  void setMaximum(qlonglong max) { QDoubleSpinBox::setMaximum(makeValue(max)); }
+  void setRange(qlonglong min, qlonglong max)
+  {
+    RDSpinBox64::setMinimum(min);
+    RDSpinBox64::setMaximum(max);
+  }
+
+  void setSingleStep(qulonglong val) { QDoubleSpinBox::setSingleStep(makeValue(val)); }
+  void setMinimum(qulonglong min) { QDoubleSpinBox::setMinimum(makeValue(min)); }
+  void setMaximum(qulonglong max) { QDoubleSpinBox::setMaximum(makeValue(max)); }
+  void setRange(qulonglong min, qulonglong max)
+  {
+    RDSpinBox64::setMinimum(min);
+    RDSpinBox64::setMaximum(max);
+  }
+
+  static qlonglong getValue(double d) { return qlonglong(d); }
+  static qulonglong getUValue(double d) { return qulonglong(d); }
+  static double makeValue(qlonglong l) { return l < 0 ? -double((-l) & mask) : double(l & mask); }
+  static double makeValue(qulonglong l) { return double(l & mask); }
+};
+
 class QMenu;
 
 // helper for doing a manual blocking invoke of a dialog
diff --git a/qrenderdoc/Windows/BufferViewer.cpp b/qrenderdoc/Windows/BufferViewer.cpp
index 45877ccba..212d1a6f3 100644
--- a/qrenderdoc/Windows/BufferViewer.cpp
+++ b/qrenderdoc/Windows/BufferViewer.cpp
@@ -1913,6 +1913,15 @@ BufferViewer::BufferViewer(ICaptureContext &ctx, bool meshview, QWidget *parent)
 {
   ui->setupUi(this);
 
+  byteRangeStart = (RDSpinBox64 *)ui->byteRangeStart;
+  byteRangeLength = (RDSpinBox64 *)ui->byteRangeLength;
+
+  byteRangeStart->configure();
+  byteRangeLength->configure();
+
+  byteRangeStart->setMinimum(0ULL);
+  byteRangeLength->setMinimum(0ULL);
+
   m_ModelVSIn = new BufferItemModel(ui->vsinData, true, meshview, this);
   m_ModelVSOut = new BufferItemModel(ui->vsoutData, false, meshview, this);
   m_ModelGSOut = new BufferItemModel(ui->gsoutData, false, meshview, this);
@@ -2129,9 +2138,9 @@ void BufferViewer::SetupMeshView()
   // hide buttons we don't want in the toolbar
   ui->byteRangeLine->setVisible(false);
   ui->byteRangeStartLabel->setVisible(false);
-  ui->byteRangeStart->setVisible(false);
+  byteRangeStart->setVisible(false);
   ui->byteRangeLengthLabel->setVisible(false);
-  ui->byteRangeLength->setVisible(false);
+  byteRangeLength->setVisible(false);
 
   ui->resourceDetails->setVisible(false);
   ui->formatSpecifier->setVisible(false);
@@ -3848,34 +3857,34 @@ void BufferViewer::processFormat(const QString &format)
 
   ui->formatSpecifier->setFormat(format);
 
-  uint32_t stride = qMax(1U, cols.type.descriptor.arrayByteStride);
+  qulonglong stride = qMax(1U, cols.type.descriptor.arrayByteStride);
 
-  ui->byteRangeStart->setSingleStep((int)stride);
-  ui->byteRangeLength->setSingleStep((int)stride);
+  byteRangeStart->setSingleStep(stride);
+  byteRangeLength->setSingleStep(stride);
 
-  ui->byteRangeStart->setMaximum((int)m_ObjectByteSize);
-  ui->byteRangeLength->setMaximum((int)m_ObjectByteSize);
+  byteRangeStart->setMaximum(m_ObjectByteSize);
+  byteRangeLength->setMaximum(m_ObjectByteSize);
 
-  ui->byteRangeStart->setValue((int)m_ByteOffset);
-  ui->byteRangeLength->setValue((int)m_ByteSize);
+  byteRangeStart->setValue(m_ByteOffset);
+  byteRangeLength->setValue(m_ByteSize);
 
   ui->formatSpecifier->setErrors(errors);
 
   OnEventChanged(m_Ctx.CurEvent());
 }
 
-void BufferViewer::on_byteRangeStart_valueChanged(int value)
+void BufferViewer::on_byteRangeStart_valueChanged(double value)
 {
-  m_ByteOffset = value;
+  m_ByteOffset = RDSpinBox64::getUValue(value);
 
   m_PagingByteOffset = 0;
 
   processFormat(m_Format);
 }
 
-void BufferViewer::on_byteRangeLength_valueChanged(int value)
+void BufferViewer::on_byteRangeLength_valueChanged(double value)
 {
-  m_ByteSize = value;
+  m_ByteSize = RDSpinBox64::getUValue(value);
 
   m_PagingByteOffset = 0;
 
diff --git a/qrenderdoc/Windows/BufferViewer.h b/qrenderdoc/Windows/BufferViewer.h
index 7c103166e..e84db8844 100644
--- a/qrenderdoc/Windows/BufferViewer.h
+++ b/qrenderdoc/Windows/BufferViewer.h
@@ -34,6 +34,7 @@ namespace Ui
 class BufferViewer;
 }
 
+class RDSpinBox64;
 class QItemSelection;
 class QMenu;
 class QPushButton;
@@ -112,8 +113,8 @@ private slots:
   void on_instance_valueChanged(int value);
   void on_viewIndex_valueChanged(int value);
   void on_rowOffset_valueChanged(int value);
-  void on_byteRangeStart_valueChanged(int value);
-  void on_byteRangeLength_valueChanged(int value);
+  void on_byteRangeStart_valueChanged(double value);
+  void on_byteRangeLength_valueChanged(double value);
 
   // manual slots
   void render_mouseMove(QMouseEvent *e);
@@ -226,6 +227,9 @@ private:
   QAction *m_ExportBytes = NULL;
   QAction *m_DebugVert = NULL;
 
+  RDSpinBox64 *byteRangeStart = NULL;
+  RDSpinBox64 *byteRangeLength = NULL;
+
   RDTableView *tableForStage(MeshDataStage stage);
   BufferItemModel *modelForStage(MeshDataStage stage);
 
diff --git a/qrenderdoc/Windows/BufferViewer.ui b/qrenderdoc/Windows/BufferViewer.ui
index de449430b..d8f18d7be 100644
--- a/qrenderdoc/Windows/BufferViewer.ui
+++ b/qrenderdoc/Windows/BufferViewer.ui
@@ -916,7 +916,7 @@ Enter 0.0 to use automatic/guessed value derived from data.</string>
      </widget>
     </item>
     <item>
-     <widget class="QSpinBox" name="byteRangeStart">
+     <widget class="QDoubleSpinBox" name="byteRangeStart">
       <property name="maximum">
        <number>999123456</number>
       </property>
@@ -930,7 +930,7 @@ Enter 0.0 to use automatic/guessed value derived from data.</string>
      </widget>
     </item>
     <item>
-     <widget class="QSpinBox" name="byteRangeLength">
+     <widget class="QDoubleSpinBox" name="byteRangeLength">
       <property name="maximum">
        <number>999123456</number>
       </property>