diff --git a/decorations/settings.cpp b/decorations/settings.cpp
index b016cdec0d..cef2038c31 100644
--- a/decorations/settings.cpp
+++ b/decorations/settings.cpp
@@ -35,6 +35,7 @@ namespace Decoration
 SettingsImpl::SettingsImpl(KDecoration2::DecorationSettings *parent)
     : QObject()
     , DecorationSettingsPrivate(parent)
+    , m_borderSize(KDecoration2::BorderSize::Normal)
 {
     readSettings();
 
diff --git a/decorations/settings.h b/decorations/settings.h
index fbde46bf81..1ec82adbb2 100644
--- a/decorations/settings.h
+++ b/decorations/settings.h
@@ -39,6 +39,9 @@ public:
     virtual ~SettingsImpl();
     bool isAlphaChannelSupported() const override;
     bool isOnAllDesktopsAvailable() const override;
+    KDecoration2::BorderSize borderSize() const override {
+        return m_borderSize;
+    }
     QList< KDecoration2::DecorationButtonType > decorationButtonsLeft() const override {
         return m_leftButtons;
     }
@@ -53,6 +56,7 @@ private:
                                                                       const QList< KDecoration2::DecorationButtonType > &defaultValue) const;
     QList< KDecoration2::DecorationButtonType > m_leftButtons;
     QList< KDecoration2::DecorationButtonType > m_rightButtons;
+    KDecoration2::BorderSize m_borderSize;
 };
 } // Decoration
 } // KWin