diff --git a/Applications/Spreadsheet/Cell.cpp b/Applications/Spreadsheet/Cell.cpp
index 4db2682a59..2192ce3d66 100644
--- a/Applications/Spreadsheet/Cell.cpp
+++ b/Applications/Spreadsheet/Cell.cpp
@@ -110,11 +110,16 @@ void Cell::update_data(Badge<Sheet>)
     if (!m_dirty)
         return;
 
+    m_js_exception = {};
+
     if (m_dirty) {
         m_dirty = false;
         if (m_kind == Formula) {
-            if (!m_evaluated_externally)
-                m_evaluated_data = m_sheet->evaluate(m_data, this);
+            if (!m_evaluated_externally) {
+                auto [value, exception] = m_sheet->evaluate(m_data, this);
+                m_evaluated_data = value;
+                m_js_exception = move(exception);
+            }
         }
 
         for (auto& ref : m_referencing_cells) {
@@ -127,19 +132,25 @@ void Cell::update_data(Badge<Sheet>)
 
     m_evaluated_formats.background_color.clear();
     m_evaluated_formats.foreground_color.clear();
-    StringBuilder builder;
-    for (auto& fmt : m_conditional_formats) {
-        if (!fmt.condition.is_empty()) {
-            builder.clear();
-            builder.append("return (");
-            builder.append(fmt.condition);
-            builder.append(')');
-            auto value = m_sheet->evaluate(builder.string_view(), this);
-            if (value.to_boolean()) {
-                if (fmt.background_color.has_value())
-                    m_evaluated_formats.background_color = fmt.background_color;
-                if (fmt.foreground_color.has_value())
-                    m_evaluated_formats.foreground_color = fmt.foreground_color;
+    if (!m_js_exception) {
+        StringBuilder builder;
+        for (auto& fmt : m_conditional_formats) {
+            if (!fmt.condition.is_empty()) {
+                builder.clear();
+                builder.append("return (");
+                builder.append(fmt.condition);
+                builder.append(')');
+                auto [value, exception] = m_sheet->evaluate(builder.string_view(), this);
+                if (exception) {
+                    m_js_exception = move(exception);
+                } else {
+                    if (value.to_boolean()) {
+                        if (fmt.background_color.has_value())
+                            m_evaluated_formats.background_color = fmt.background_color;
+                        if (fmt.foreground_color.has_value())
+                            m_evaluated_formats.foreground_color = fmt.foreground_color;
+                    }
+                }
             }
         }
     }
@@ -193,6 +204,8 @@ void Cell::copy_from(const Cell& other)
     m_type_metadata = other.m_type_metadata;
     m_conditional_formats = other.m_conditional_formats;
     m_evaluated_formats = other.m_evaluated_formats;
+    if (!other.m_js_exception)
+        m_js_exception = other.m_js_exception;
 }
 
 }
diff --git a/Applications/Spreadsheet/Cell.h b/Applications/Spreadsheet/Cell.h
index 19e63e1328..2487a43d4e 100644
--- a/Applications/Spreadsheet/Cell.h
+++ b/Applications/Spreadsheet/Cell.h
@@ -67,6 +67,10 @@ struct Cell : public Weakable<Cell> {
     void set_data(String new_data);
     void set_data(JS::Value new_data);
     bool dirty() const { return m_dirty; }
+    void clear_dirty() { m_dirty = false; }
+
+    void set_exception(JS::Exception* exc) { m_js_exception = exc; }
+    JS::Exception* exception() const { return m_js_exception; }
 
     const String& data() const { return m_data; }
     const JS::Value& evaluated_data() const { return m_evaluated_data; }
@@ -117,6 +121,7 @@ private:
     bool m_evaluated_externally { false };
     String m_data;
     JS::Value m_evaluated_data;
+    JS::Exception* m_js_exception { nullptr };
     Kind m_kind { LiteralString };
     WeakPtr<Sheet> m_sheet;
     Vector<WeakPtr<Cell>> m_referencing_cells;
diff --git a/Applications/Spreadsheet/CellType/Date.cpp b/Applications/Spreadsheet/CellType/Date.cpp
index eb0937ed55..005620006f 100644
--- a/Applications/Spreadsheet/CellType/Date.cpp
+++ b/Applications/Spreadsheet/CellType/Date.cpp
@@ -27,6 +27,7 @@
 #include "Date.h"
 #include "../Cell.h"
 #include "../Spreadsheet.h"
+#include <AK/ScopeGuard.h>
 #include <LibCore/DateTime.h>
 
 namespace Spreadsheet {
@@ -42,6 +43,12 @@ DateCell::~DateCell()
 
 String DateCell::display(Cell& cell, const CellTypeMetadata& metadata) const
 {
+    ScopeGuard propagate_exception { [&cell] {
+        if (auto exc = cell.sheet().interpreter().exception()) {
+            cell.sheet().interpreter().vm().clear_exception();
+            cell.set_exception(exc);
+        }
+    } };
     auto timestamp = js_value(cell, metadata);
     auto string = Core::DateTime::from_timestamp(timestamp.to_i32(cell.sheet().global_object())).to_string(metadata.format.is_empty() ? "%Y-%m-%d %H:%M:%S" : metadata.format.characters());
 
@@ -53,7 +60,8 @@ String DateCell::display(Cell& cell, const CellTypeMetadata& metadata) const
 
 JS::Value DateCell::js_value(Cell& cell, const CellTypeMetadata&) const
 {
-    auto value = cell.js_data().to_double(cell.sheet().global_object());
+    auto js_data = cell.js_data();
+    auto value = js_data.to_double(cell.sheet().global_object());
     return JS::Value(value / 1000); // Turn it to seconds
 }
 
diff --git a/Applications/Spreadsheet/CellType/Numeric.cpp b/Applications/Spreadsheet/CellType/Numeric.cpp
index b69ca1bf21..d58d48cd85 100644
--- a/Applications/Spreadsheet/CellType/Numeric.cpp
+++ b/Applications/Spreadsheet/CellType/Numeric.cpp
@@ -28,6 +28,7 @@
 #include "../Cell.h"
 #include "../Spreadsheet.h"
 #include "Format.h"
+#include <AK/ScopeGuard.h>
 
 namespace Spreadsheet {
 
@@ -42,6 +43,12 @@ NumericCell::~NumericCell()
 
 String NumericCell::display(Cell& cell, const CellTypeMetadata& metadata) const
 {
+    ScopeGuard propagate_exception { [&cell] {
+        if (auto exc = cell.sheet().interpreter().exception()) {
+            cell.sheet().interpreter().vm().clear_exception();
+            cell.set_exception(exc);
+        }
+    } };
     auto value = js_value(cell, metadata);
     String string;
     if (metadata.format.is_empty())
@@ -57,6 +64,12 @@ String NumericCell::display(Cell& cell, const CellTypeMetadata& metadata) const
 
 JS::Value NumericCell::js_value(Cell& cell, const CellTypeMetadata&) const
 {
+    ScopeGuard propagate_exception { [&cell] {
+        if (auto exc = cell.sheet().interpreter().exception()) {
+            cell.sheet().interpreter().vm().clear_exception();
+            cell.set_exception(exc);
+        }
+    } };
     return cell.js_data().to_number(cell.sheet().global_object());
 }
 
diff --git a/Applications/Spreadsheet/JSIntegration.cpp b/Applications/Spreadsheet/JSIntegration.cpp
index 7c94cda388..5feddc9bf2 100644
--- a/Applications/Spreadsheet/JSIntegration.cpp
+++ b/Applications/Spreadsheet/JSIntegration.cpp
@@ -87,6 +87,16 @@ void SheetGlobalObject::initialize()
     define_native_function("column_index", column_index, 1);
 }
 
+void SheetGlobalObject::visit_edges(Visitor& visitor)
+{
+    GlobalObject::visit_edges(visitor);
+    for (auto& it : m_sheet.cells()) {
+        if (it.value->exception())
+            visitor.visit(it.value->exception());
+        visitor.visit(it.value->evaluated_data());
+    }
+}
+
 JS_DEFINE_NATIVE_FUNCTION(SheetGlobalObject::parse_cell_name)
 {
     if (vm.argument_count() != 1) {
@@ -231,6 +241,13 @@ void WorkbookObject::initialize(JS::GlobalObject& global_object)
     define_native_function("sheet", sheet, 1);
 }
 
+void WorkbookObject::visit_edges(Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    for (auto& sheet : m_workbook.sheets())
+        visitor.visit(&sheet.global_object());
+}
+
 JS_DEFINE_NATIVE_FUNCTION(WorkbookObject::sheet)
 {
     if (vm.argument_count() != 1) {
diff --git a/Applications/Spreadsheet/JSIntegration.h b/Applications/Spreadsheet/JSIntegration.h
index 995694d8a1..4ad289e61f 100644
--- a/Applications/Spreadsheet/JSIntegration.h
+++ b/Applications/Spreadsheet/JSIntegration.h
@@ -50,6 +50,7 @@ public:
     JS_DECLARE_NATIVE_FUNCTION(column_arithmetic);
 
 private:
+    virtual void visit_edges(Visitor&) override;
     Sheet& m_sheet;
 };
 
@@ -66,6 +67,7 @@ public:
     JS_DECLARE_NATIVE_FUNCTION(sheet);
 
 private:
+    virtual void visit_edges(Visitor&) override;
     Workbook& m_workbook;
 };
 
diff --git a/Applications/Spreadsheet/Spreadsheet.cpp b/Applications/Spreadsheet/Spreadsheet.cpp
index 881dfb4abf..3ff03b0916 100644
--- a/Applications/Spreadsheet/Spreadsheet.cpp
+++ b/Applications/Spreadsheet/Spreadsheet.cpp
@@ -59,10 +59,11 @@ Sheet::Sheet(const StringView& name, Workbook& workbook)
 Sheet::Sheet(Workbook& workbook)
     : m_workbook(workbook)
 {
+    JS::DeferGC defer_gc(m_workbook.interpreter().heap());
     m_global_object = m_workbook.interpreter().heap().allocate_without_global_object<SheetGlobalObject>(*this);
-    m_global_object->initialize();
-    m_global_object->put("workbook", m_workbook.workbook_object());
-    m_global_object->put("thisSheet", m_global_object); // Self-reference is unfortunate, but required.
+    global_object().initialize();
+    global_object().put("workbook", m_workbook.workbook_object());
+    global_object().put("thisSheet", &global_object()); // Self-reference is unfortunate, but required.
 
     // Sadly, these have to be evaluated once per sheet.
     auto file_or_error = Core::File::open("/res/js/Spreadsheet/runtime.js", Core::IODevice::OpenMode::ReadOnly);
@@ -179,26 +180,26 @@ void Sheet::update(Cell& cell)
     }
 }
 
-JS::Value Sheet::evaluate(const StringView& source, Cell* on_behalf_of)
+Sheet::ValueAndException Sheet::evaluate(const StringView& source, Cell* on_behalf_of)
 {
     TemporaryChange cell_change { m_current_cell_being_evaluated, on_behalf_of };
+    ScopeGuard clear_exception { [&] { interpreter().vm().clear_exception(); } };
 
     auto parser = JS::Parser(JS::Lexer(source));
-    if (parser.has_errors())
-        return JS::js_undefined();
+    if (parser.has_errors() || interpreter().exception())
+        return { JS::js_undefined(), interpreter().exception() };
 
     auto program = parser.parse_program();
     interpreter().run(global_object(), program);
     if (interpreter().exception()) {
-        auto exc = interpreter().exception()->value();
-        interpreter().vm().clear_exception();
-        return exc;
+        auto exc = interpreter().exception();
+        return { JS::js_undefined(), exc };
     }
 
     auto value = interpreter().vm().last_value();
     if (value.is_empty())
-        return JS::js_undefined();
-    return value;
+        return { JS::js_undefined(), {} };
+    return { value, {} };
 }
 
 Cell* Sheet::at(const StringView& name)
diff --git a/Applications/Spreadsheet/Spreadsheet.h b/Applications/Spreadsheet/Spreadsheet.h
index 23fb45d4b1..ab9ecb62d8 100644
--- a/Applications/Spreadsheet/Spreadsheet.h
+++ b/Applications/Spreadsheet/Spreadsheet.h
@@ -118,7 +118,11 @@ public:
     void update();
     void update(Cell&);
 
-    JS::Value evaluate(const StringView&, Cell* = nullptr);
+    struct ValueAndException {
+        JS::Value value;
+        JS::Exception* exception { nullptr };
+    };
+    ValueAndException evaluate(const StringView&, Cell* = nullptr);
     JS::Interpreter& interpreter() const;
     SheetGlobalObject& global_object() const { return *m_global_object; }
 
diff --git a/Applications/Spreadsheet/SpreadsheetModel.cpp b/Applications/Spreadsheet/SpreadsheetModel.cpp
index 2c3826801e..84b34a5e99 100644
--- a/Applications/Spreadsheet/SpreadsheetModel.cpp
+++ b/Applications/Spreadsheet/SpreadsheetModel.cpp
@@ -37,16 +37,6 @@ SheetModel::~SheetModel()
 {
 }
 
-static inline JS::Object* as_error(JS::Value value)
-{
-    if (value.is_object()) {
-        auto& object = value.as_object();
-        return object.is_error() ? &object : nullptr;
-    }
-
-    return nullptr;
-}
-
 GUI::Variant SheetModel::data(const GUI::ModelIndex& index, GUI::ModelRole role) const
 {
     if (!index.is_valid())
@@ -58,10 +48,22 @@ GUI::Variant SheetModel::data(const GUI::ModelIndex& index, GUI::ModelRole role)
             return String::empty();
 
         if (cell->kind() == Spreadsheet::Cell::Formula) {
-            if (auto object = as_error(cell->evaluated_data())) {
+            if (auto exception = cell->exception()) {
                 StringBuilder builder;
-                auto error = object->get("message").to_string_without_side_effects();
                 builder.append("Error: ");
+                auto value = exception->value();
+                if (value.is_object()) {
+                    auto& object = value.as_object();
+                    if (object.is_error()) {
+                        auto error = object.get("message").to_string_without_side_effects();
+                        builder.append(error);
+                        return builder.to_string();
+                    }
+                }
+                auto error = value.to_string(cell->sheet().global_object());
+                // This is annoying, but whatever.
+                cell->sheet().interpreter().vm().clear_exception();
+
                 builder.append(error);
                 return builder.to_string();
             }
@@ -87,7 +89,7 @@ GUI::Variant SheetModel::data(const GUI::ModelIndex& index, GUI::ModelRole role)
             return {};
 
         if (cell->kind() == Spreadsheet::Cell::Formula) {
-            if (as_error(cell->evaluated_data()))
+            if (cell->exception())
                 return Color(Color::Red);
         }
 
diff --git a/Libraries/LibJS/AST.cpp b/Libraries/LibJS/AST.cpp
index 154c3a2719..563a278f84 100644
--- a/Libraries/LibJS/AST.cpp
+++ b/Libraries/LibJS/AST.cpp
@@ -51,7 +51,7 @@
 
 namespace JS {
 
-static void update_function_name(Value value, const FlyString& name, HashTable<const JS::Cell*>& visited)
+static void update_function_name(Value value, const FlyString& name, HashTable<JS::Cell*>& visited)
 {
     if (!value.is_object())
         return;
@@ -73,7 +73,7 @@ static void update_function_name(Value value, const FlyString& name, HashTable<c
 
 static void update_function_name(Value value, const FlyString& name)
 {
-    HashTable<const JS::Cell*> visited;
+    HashTable<JS::Cell*> visited;
     update_function_name(value, name, visited);
 }
 
diff --git a/Libraries/LibJS/Heap/Handle.h b/Libraries/LibJS/Heap/Handle.h
index e2686395fc..33fb022d21 100644
--- a/Libraries/LibJS/Heap/Handle.h
+++ b/Libraries/LibJS/Heap/Handle.h
@@ -65,6 +65,8 @@ public:
     T* cell() { return static_cast<T*>(m_impl->cell()); }
     const T* cell() const { return static_cast<const T*>(m_impl->cell()); }
 
+    bool is_null() const { return m_impl.is_null(); }
+
 private:
     explicit Handle(NonnullRefPtr<HandleImpl> impl)
         : m_impl(move(impl))