diff --git a/src/interface/node.h b/src/interface/node.h
--- a/src/interface/node.h
+++ b/src/interface/node.h
@@ -64,6 +64,9 @@
     //! Start shutdown.
     virtual void startShutdown() = 0;
 
+    //! Return whether shutdown was requested.
+    virtual bool shutdownRequested() = 0;
+
     //! Map port.
     virtual void mapPort(bool use_upnp) = 0;
 
@@ -73,6 +76,18 @@
     //! Register handler for init messages.
     using InitMessageFn = std::function<void(const std::string &message)>;
     virtual std::unique_ptr<Handler> handleInitMessage(InitMessageFn fn) = 0;
+
+    //! Register handler for message box messages.
+    using MessageBoxFn =
+        std::function<bool(const std::string &message,
+                           const std::string &caption, unsigned int style)>;
+    virtual std::unique_ptr<Handler> handleMessageBox(MessageBoxFn fn) = 0;
+
+    //! Register handler for question messages.
+    using QuestionFn = std::function<bool(
+        const std::string &message, const std::string &non_interactive_message,
+        const std::string &caption, unsigned int style)>;
+    virtual std::unique_ptr<Handler> handleQuestion(QuestionFn fn) = 0;
 };
 
 //! Return implementation of Node interface.
diff --git a/src/interface/node.cpp b/src/interface/node.cpp
--- a/src/interface/node.cpp
+++ b/src/interface/node.cpp
@@ -60,6 +60,7 @@
             Shutdown();
         }
         void startShutdown() override { StartShutdown(); }
+        bool shutdownRequested() override { return ShutdownRequested(); }
         void mapPort(bool use_upnp) override {
             if (use_upnp) {
                 StartMapPort();
@@ -74,6 +75,12 @@
         std::unique_ptr<Handler> handleInitMessage(InitMessageFn fn) override {
             return MakeHandler(::uiInterface.InitMessage.connect(fn));
         }
+        std::unique_ptr<Handler> handleMessageBox(MessageBoxFn fn) override {
+            return MakeHandler(::uiInterface.ThreadSafeMessageBox.connect(fn));
+        }
+        std::unique_ptr<Handler> handleQuestion(QuestionFn fn) override {
+            return MakeHandler(::uiInterface.ThreadSafeQuestion.connect(fn));
+        }
     };
 
 } // namespace
diff --git a/src/qt/bitcoin.cpp b/src/qt/bitcoin.cpp
--- a/src/qt/bitcoin.cpp
+++ b/src/qt/bitcoin.cpp
@@ -350,7 +350,7 @@
 
 void BitcoinApplication::createWindow(const Config *config,
                                       const NetworkStyle *networkStyle) {
-    window = new BitcoinGUI(config, platformStyle, networkStyle, 0);
+    window = new BitcoinGUI(m_node, config, platformStyle, networkStyle, 0);
 
     pollShutdownTimer = new QTimer(window);
     connect(pollShutdownTimer, SIGNAL(timeout()), window,
diff --git a/src/qt/bitcoingui.h b/src/qt/bitcoingui.h
--- a/src/qt/bitcoingui.h
+++ b/src/qt/bitcoingui.h
@@ -18,6 +18,8 @@
 #include <QPoint>
 #include <QSystemTrayIcon>
 
+#include <memory>
+
 class ClientModel;
 class NetworkStyle;
 class Notificator;
@@ -34,6 +36,11 @@
 class Config;
 class CWallet;
 
+namespace interface {
+class Handler;
+class Node;
+}
+
 QT_BEGIN_NAMESPACE
 class QAction;
 class QComboBox;
@@ -52,7 +59,8 @@
 public:
     static const std::string DEFAULT_UIPLATFORM;
 
-    explicit BitcoinGUI(const Config *, const PlatformStyle *platformStyle,
+    explicit BitcoinGUI(interface::Node &node, const Config *,
+                        const PlatformStyle *platformStyle,
                         const NetworkStyle *networkStyle, QWidget *parent = 0);
     ~BitcoinGUI();
 
@@ -83,6 +91,9 @@
     bool eventFilter(QObject *object, QEvent *event) override;
 
 private:
+    interface::Node &m_node;
+    std::unique_ptr<interface::Handler> m_handler_message_box;
+    std::unique_ptr<interface::Handler> m_handler_question;
     ClientModel *clientModel = nullptr;
     WalletFrame *walletFrame = nullptr;
 
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -34,6 +34,8 @@
 
 #include "chainparams.h"
 #include "init.h"
+#include "interface/handler.h"
+#include "interface/node.h"
 #include "ui_interface.h"
 #include "util.h"
 
@@ -70,11 +72,11 @@
 #endif
     ;
 
-BitcoinGUI::BitcoinGUI(const Config *configIn,
+BitcoinGUI::BitcoinGUI(interface::Node &node, const Config *configIn,
                        const PlatformStyle *_platformStyle,
                        const NetworkStyle *networkStyle, QWidget *parent)
-    : QMainWindow(parent), enableWallet(false), platformStyle(_platformStyle),
-      config(configIn) {
+    : QMainWindow(parent), enableWallet(false), m_node(node),
+      platformStyle(_platformStyle), config(configIn) {
     QSettings settings;
     if (!restoreGeometry(settings.value("MainWindowGeometry").toByteArray())) {
         // Restore failed (perhaps missing setting), center the window
@@ -1184,7 +1186,7 @@
 }
 
 void BitcoinGUI::detectShutdown() {
-    if (ShutdownRequested()) {
+    if (m_node.shutdownRequested()) {
         if (rpcConsole) {
             rpcConsole->hide();
         }
@@ -1244,18 +1246,16 @@
 
 void BitcoinGUI::subscribeToCoreSignals() {
     // Connect signals to client
-    uiInterface.ThreadSafeMessageBox.connect(
+    m_handler_message_box = m_node.handleMessageBox(
         boost::bind(ThreadSafeMessageBox, this, _1, _2, _3));
-    uiInterface.ThreadSafeQuestion.connect(
+    m_handler_question = m_node.handleQuestion(
         boost::bind(ThreadSafeMessageBox, this, _1, _3, _4));
 }
 
 void BitcoinGUI::unsubscribeFromCoreSignals() {
     // Disconnect signals from client
-    uiInterface.ThreadSafeMessageBox.disconnect(
-        boost::bind(ThreadSafeMessageBox, this, _1, _2, _3));
-    uiInterface.ThreadSafeQuestion.disconnect(
-        boost::bind(ThreadSafeMessageBox, this, _1, _3, _4));
+    m_handler_message_box->disconnect();
+    m_handler_question->disconnect();
 }
 
 void BitcoinGUI::toggleNetworkActive() {