diff --git a/src/misc_gui.cpp b/src/misc_gui.cpp
index c25cea77a4..49a46e5b1c 100644
--- a/src/misc_gui.cpp
+++ b/src/misc_gui.cpp
@@ -971,7 +971,7 @@ struct QueryStringWindow : public Window
 
 		this->editbox.text.UpdateSize();
 
-		if ((flags & QSF_ACCEPT_UNCHANGED) == 0) this->editbox.orig = stredup(this->editbox.text.buf);
+		if ((flags & QSF_ACCEPT_UNCHANGED) == 0) this->editbox.orig = this->editbox.text.buf;
 
 		this->querystrings[WID_QS_TEXT] = &this->editbox;
 		this->editbox.caption = caption;
@@ -1033,7 +1033,7 @@ struct QueryStringWindow : public Window
 
 	void OnOk()
 	{
-		if (this->editbox.orig == nullptr || strcmp(this->editbox.text.buf, this->editbox.orig) != 0) {
+		if (!this->editbox.orig.has_value() || this->editbox.text.buf != this->editbox.orig) {
 			assert(this->parent != nullptr);
 
 			this->parent->OnQueryTextFinished(this->editbox.text.buf);
diff --git a/src/osk_gui.cpp b/src/osk_gui.cpp
index 1cfbfc8ace..b6f946c791 100644
--- a/src/osk_gui.cpp
+++ b/src/osk_gui.cpp
@@ -39,7 +39,7 @@ struct OskWindow : public Window {
 	QueryString *qs;       ///< text-input
 	int text_btn;          ///< widget number of parent's text field
 	Textbuf *text;         ///< pointer to parent's textbuffer (to update caret position)
-	char *orig_str_buf;    ///< Original string.
+	std::string orig_str;  ///< Original string.
 	bool shift;            ///< Is the shift effectively pressed?
 
 	OskWindow(WindowDesc *desc, Window *parent, int button) : Window(desc)
@@ -58,7 +58,7 @@ struct OskWindow : public Window {
 		this->querystrings[WID_OSK_TEXT] = this->qs;
 
 		/* make a copy in case we need to reset later */
-		this->orig_str_buf = stredup(this->qs->text.buf);
+		this->orig_str = this->qs->text.buf;
 
 		this->InitNested(0);
 		this->SetFocusedWidget(WID_OSK_TEXT);
@@ -69,11 +69,6 @@ struct OskWindow : public Window {
 		this->UpdateOskState();
 	}
 
-	~OskWindow()
-	{
-		free(this->orig_str_buf);
-	}
-
 	/**
 	 * Only show valid characters; do not show characters that would
 	 * only insert a space when we have a spacebar to do that or
@@ -162,7 +157,7 @@ struct OskWindow : public Window {
 				break;
 
 			case WID_OSK_OK:
-				if (this->qs->orig == nullptr || strcmp(this->qs->text.buf, this->qs->orig) != 0) {
+				if (!this->qs->orig.has_value() || this->qs->text.buf != this->qs->orig) {
 					/* pass information by simulating a button press on parent window */
 					if (this->qs->ok_button >= 0) {
 						this->parent->OnClick(pt, this->qs->ok_button, 1);
@@ -179,7 +174,7 @@ struct OskWindow : public Window {
 					/* Window gets deleted when the parent window removes itself. */
 					return;
 				} else { // or reset to original string
-					qs->text.Assign(this->orig_str_buf);
+					qs->text.Assign(this->orig_str);
 					qs->text.MovePos(WKC_END);
 					this->OnEditboxChanged(WID_OSK_TEXT);
 					this->Close();
@@ -425,8 +420,7 @@ void UpdateOSKOriginalText(const Window *parent, int button)
 	OskWindow *osk = dynamic_cast<OskWindow *>(FindWindowById(WC_OSK, 0));
 	if (osk == nullptr || osk->parent != parent || osk->text_btn != button) return;
 
-	free(osk->orig_str_buf);
-	osk->orig_str_buf = stredup(osk->qs->text.buf);
+	osk->orig_str = osk->qs->text.buf;
 
 	osk->SetDirty();
 }
diff --git a/src/querystring_gui.h b/src/querystring_gui.h
index 79eadc7993..bd8ccb7a88 100644
--- a/src/querystring_gui.h
+++ b/src/querystring_gui.h
@@ -27,7 +27,7 @@ struct QueryString {
 	int ok_button;      ///< Widget button of parent window to simulate when pressing OK in OSK.
 	int cancel_button;  ///< Widget button of parent window to simulate when pressing CANCEL in OSK.
 	Textbuf text;
-	const char *orig;
+	std::optional<std::string> orig;
 	bool handled;
 
 	/**
@@ -35,18 +35,10 @@ struct QueryString {
 	 * @param size Maximum size in bytes.
 	 * @param chars Maximum size in chars.
 	 */
-	QueryString(uint16 size, uint16 chars = UINT16_MAX) : ok_button(ACTION_NOTHING), cancel_button(ACTION_DESELECT), text(size, chars), orig(nullptr)
+	QueryString(uint16 size, uint16 chars = UINT16_MAX) : ok_button(ACTION_NOTHING), cancel_button(ACTION_DESELECT), text(size, chars)
 	{
 	}
 
-	/**
-	 * Make sure everything gets freed.
-	 */
-	~QueryString()
-	{
-		free(this->orig);
-	}
-
 public:
 	void DrawEditBox(const Window *w, int wid) const;
 	void ClickEditBox(Window *w, Point pt, int wid, int click_count, bool focus_changed);