diff --git a/AK/AKString.h b/AK/AKString.h
index 4f9b8ec84a..20ee499de2 100644
--- a/AK/AKString.h
+++ b/AK/AKString.h
@@ -39,6 +39,11 @@ public:
     {
     }
 
+    String(const StringImpl* impl)
+        : m_impl(const_cast<StringImpl*>(impl))
+    {
+    }
+
     String(RetainPtr<StringImpl>&& impl)
         : m_impl(move(impl))
     {
diff --git a/LibGUI/GVariant.cpp b/LibGUI/GVariant.cpp
index 958d66ad38..196249d8a0 100644
--- a/LibGUI/GVariant.cpp
+++ b/LibGUI/GVariant.cpp
@@ -6,6 +6,11 @@ GVariant::GVariant()
 }
 
 GVariant::~GVariant()
+{
+    clear();
+}
+
+void GVariant::clear()
 {
     switch (m_type) {
     case Type::String:
@@ -20,6 +25,8 @@ GVariant::~GVariant()
     default:
         break;
     }
+    m_type = Type::Invalid;
+    m_value.as_string = nullptr;
 }
 
 GVariant::GVariant(int value)
@@ -85,9 +92,24 @@ GVariant::GVariant(const Rect& rect)
     m_value.as_rect = (const RawRect&)rect;
 }
 
-GVariant::GVariant(const GVariant& other)
-    : m_type(other.m_type)
+GVariant& GVariant::operator=(const GVariant& other)
 {
+    if (&other == this)
+        return *this;
+    clear();
+    copy_from(other);
+    return *this;
+}
+
+GVariant::GVariant(const GVariant& other)
+{
+    copy_from(other);
+}
+
+void GVariant::copy_from(const GVariant& other)
+{
+    ASSERT(!is_valid());
+    m_type = other.m_type;
     switch (m_type) {
     case Type::Bool:
         m_value.as_bool = other.m_value.as_bool;
@@ -214,6 +236,7 @@ String GVariant::to_string() const
     case Type::Rect:
         return as_rect().to_string();
     case Type::Invalid:
+        return "[Null]";
         break;
     }
     ASSERT_NOT_REACHED();
diff --git a/LibGUI/GVariant.h b/LibGUI/GVariant.h
index 83a97008a3..08c9301021 100644
--- a/LibGUI/GVariant.h
+++ b/LibGUI/GVariant.h
@@ -19,6 +19,12 @@ public:
     GVariant(Color);
 
     GVariant(const GVariant&);
+    GVariant& operator=(const GVariant&);
+
+    GVariant(GVariant&&) = delete;
+    GVariant& operator=(GVariant&&) = delete;
+
+    void clear();
     ~GVariant();
 
     enum class Type {
@@ -84,7 +90,7 @@ public:
     String as_string() const
     {
         ASSERT(type() == Type::String);
-        return *m_value.as_string;
+        return m_value.as_string;
     }
 
     const GraphicsBitmap& as_bitmap() const
@@ -118,6 +124,8 @@ public:
     bool operator<(const GVariant&) const;
 
 private:
+    void copy_from(const GVariant&);
+
     struct RawPoint {
         int x;
         int y;