diff --git a/Userland/Libraries/LibGUI/TextDocument.cpp b/Userland/Libraries/LibGUI/TextDocument.cpp
index 075265f2be..6e0d7728c4 100644
--- a/Userland/Libraries/LibGUI/TextDocument.cpp
+++ b/Userland/Libraries/LibGUI/TextDocument.cpp
@@ -26,6 +26,7 @@ TextDocument::TextDocument(Client* client)
     if (client)
         m_clients.set(client);
     append_line(make<TextDocumentLine>(*this));
+    set_modified(false);
 
     // TODO: Instead of a repating timer, this we should call a delayed 2 sec timer when the user types.
     m_undo_timer = Core::Timer::construct(
@@ -91,6 +92,9 @@ bool TextDocument::set_text(const StringView& text)
         client->document_did_set_text();
 
     clear_text_guard.disarm();
+
+    // FIXME: Should the modified state be cleared on some of the earlier returns as well?
+    set_modified(false);
     return true;
 }
 
@@ -305,6 +309,8 @@ void TextDocument::update_views(Badge<TextDocumentLine>)
 
 void TextDocument::notify_did_change()
 {
+    set_modified(true);
+
     if (m_client_notifications_enabled) {
         for (auto* client : m_clients)
             client->document_did_change();
@@ -878,4 +884,9 @@ const TextDocumentSpan* TextDocument::span_at(const TextPosition& position) cons
     return nullptr;
 }
 
+void TextDocument::set_modified(bool modified)
+{
+    m_modified = modified;
+}
+
 }
diff --git a/Userland/Libraries/LibGUI/TextDocument.h b/Userland/Libraries/LibGUI/TextDocument.h
index bd711685d7..d73f505799 100644
--- a/Userland/Libraries/LibGUI/TextDocument.h
+++ b/Userland/Libraries/LibGUI/TextDocument.h
@@ -122,6 +122,8 @@ public:
     virtual bool is_code_document() const { return false; }
 
     bool is_empty() const;
+    bool is_modified() const { return m_modified; }
+    void set_modified(bool);
 
 protected:
     explicit TextDocument(Client* client);
@@ -134,6 +136,7 @@ private:
 
     HashTable<Client*> m_clients;
     bool m_client_notifications_enabled { true };
+    bool m_modified { false };
 
     UndoStack m_undo_stack;
     RefPtr<Core::Timer> m_undo_timer;