diff --git a/src/osx/core/display.cpp b/src/osx/core/display.cpp
index 796a7ef7cb..1892743377 100644
--- a/src/osx/core/display.cpp
+++ b/src/osx/core/display.cpp
@@ -104,6 +104,7 @@ public:
     virtual wxRect GetClientArea() const wxOVERRIDE;
     virtual int GetDepth() const wxOVERRIDE;
     virtual wxSize GetSizeMM() const wxOVERRIDE;
+    virtual double GetScaleFactor() const wxOVERRIDE;
 
     virtual wxArrayVideoModes GetModes(const wxVideoMode& mode) const wxOVERRIDE;
     virtual wxVideoMode GetCurrentMode() const wxOVERRIDE;
@@ -270,6 +271,14 @@ wxSize wxDisplayImplMacOSX::GetSizeMM() const
     return wxGetDisplaySizeMM(m_id);
 }
 
+double wxDisplayImplMacOSX::GetScaleFactor() const
+{
+    wxCFRef<CGDisplayModeRef> mode = CGDisplayCopyDisplayMode(m_id);
+    size_t width = CGDisplayModeGetWidth(mode);
+    size_t pixelsw = CGDisplayModeGetPixelWidth(mode);
+    return (double)pixelsw / width;
+}
+
 static int wxOSXCGDisplayModeGetBitsPerPixel( CGDisplayModeRef theValue )
 {
     wxCFRef<CFStringRef> pixelEncoding( CGDisplayModeCopyPixelEncoding(theValue) );