diff --git a/apps/variable_box_controller.cpp b/apps/variable_box_controller.cpp
index 904cee784..66bfb5bd9 100644
--- a/apps/variable_box_controller.cpp
+++ b/apps/variable_box_controller.cpp
@@ -17,6 +17,7 @@ using namespace Ion;
 VariableBoxController::VariableBoxController() :
   NestedMenuController(nullptr, I18n::Message::Variables),
   m_currentPage(Page::RootMenu),
+  m_lockPageDelete(Page::RootMenu),
   m_firstMemoizedLayoutIndex(0)
 {
 }
@@ -42,9 +43,12 @@ void VariableBoxController::viewDidDisappear() {
 }
 
 bool VariableBoxController::handleEvent(Ion::Events::Event event) {
-  /* We do not want to handle backspace event in that case if the empty
-   * controller is on. */
-  if (event == Ion::Events::Backspace && m_currentPage != Page::RootMenu && !isDisplayingEmptyController()) {
+  /* We do not want to handle backspace event if:
+   * - On the root menu page
+   *   The deletion on the current page is locked
+   * - The empty controller is displayed
+   */
+  if (event == Ion::Events::Backspace && m_currentPage != Page::RootMenu && m_lockPageDelete != m_currentPage && !isDisplayingEmptyController()) {
     Storage::Record record = recordAtIndex(selectedRow());
     record.destroy();
     int newSelectedRow = selectedRow() >= numberOfRows() ? numberOfRows()-1 : selectedRow();
@@ -118,6 +122,10 @@ int VariableBoxController::typeAtLocation(int i, int j) {
   return 0;
 }
 
+void VariableBoxController::lockDeleteEvent(Page page) {
+  m_lockPageDelete = page;
+}
+
 ExpressionTableCellWithExpression * VariableBoxController::leafCellAtIndex(int index) {
   assert(index >= 0 && index < k_maxNumberOfDisplayedRows);
   return &m_leafCells[index];
@@ -211,10 +219,12 @@ Layout VariableBoxController::expressionLayoutForRecord(Storage::Record record,
 }
 
 const char * VariableBoxController::extension() const {
+  assert(m_currentPage != Page::RootMenu);
   return m_currentPage == Page::Function ? GlobalContext::funcExtension : GlobalContext::expExtension;
 }
 
 Storage::Record VariableBoxController::recordAtIndex(int rowIndex) {
+  assert(m_currentPage != Page::RootMenu);
   assert(!Storage::sharedStorage()->recordWithExtensionAtIndex(extension(), rowIndex).isNull());
   return Storage::sharedStorage()->recordWithExtensionAtIndex(extension(), rowIndex);
 }
diff --git a/apps/variable_box_controller.h b/apps/variable_box_controller.h
index 26505c567..911953f09 100644
--- a/apps/variable_box_controller.h
+++ b/apps/variable_box_controller.h
@@ -27,12 +27,13 @@ public:
   int typeAtLocation(int i, int j) override;
 
   // Menu
-private:
   enum class Page {
     RootMenu = 0,
     Expression = 1,
     Function = 2
   };
+  void lockDeleteEvent(Page page);
+private:
   // TODO: use the "(x)" define in CartesianFunctionSomething
   constexpr static int k_functionArgLength = 3;
   constexpr static const char * k_functionArg = "(x)";
@@ -52,6 +53,7 @@ private:
   bool displayEmptyController();
   bool isDisplayingEmptyController() { return StackViewController::depth() == 2; }
   Page m_currentPage;
+  Page m_lockPageDelete;
   ExpressionTableCellWithExpression m_leafCells[k_maxNumberOfDisplayedRows];
   MessageTableCellWithChevron m_nodeCells[k_numberOfMenuRows];
   VariableBoxEmptyController m_emptyViewController;