diff --git a/src/include/tc_readable.h b/src/include/tc_readable.h
index ab971ae..79f5952 100644
--- a/src/include/tc_readable.h
+++ b/src/include/tc_readable.h
@@ -26,7 +26,7 @@ typedef struct tc_readable_node_t_{
     bool constant;
     // Instead of an update callback store the value for constants
     union {
-        tc_readable_result_t (*value_callback)(struct tc_readable_node_t_*);
+        tc_readable_result_t (*value_callback)(const struct tc_readable_node_t_*);
         tc_variant_t data;
     };
     struct tc_readable_node_t_ *parent;
diff --git a/src/modules/interface/qt/widgets/ReadableDisplay.cpp b/src/modules/interface/qt/widgets/ReadableDisplay.cpp
new file mode 100644
index 0000000..bc4e445
--- /dev/null
+++ b/src/modules/interface/qt/widgets/ReadableDisplay.cpp
@@ -0,0 +1,4 @@
+#include "ReadableDisplay.h"
+
+ReadableDisplay::ReadableDisplay(QWidget *parent) : QWidget(parent) {
+}
diff --git a/src/modules/interface/qt/widgets/ReadableDisplay.h b/src/modules/interface/qt/widgets/ReadableDisplay.h
new file mode 100644
index 0000000..45e5236
--- /dev/null
+++ b/src/modules/interface/qt/widgets/ReadableDisplay.h
@@ -0,0 +1,8 @@
+#pragma once
+
+#include <QWidget>
+
+class ReadableDisplay : public QWidget {
+public:
+    ReadableDisplay(QWidget *parent = nullptr);
+};