diff --git a/rtgui/rtscalable.cc b/rtgui/rtscalable.cc
index b5de0605f..421df6c10 100644
--- a/rtgui/rtscalable.cc
+++ b/rtgui/rtscalable.cc
@@ -42,12 +42,12 @@ void RTScalable::setDPInScale (const double newDPI, const int newScale)
         // HOMBRE: On windows, if scale = 2, the dpi is non significant, i.e. should be considered = 192 ; don't know for linux/macos
         dpi = newDPI;
         if (scale == 1) {
-            if (dpi >= 192.) {
+            if (dpi >= baseHiDPI) {
                 scale = 2;
             }
         }
         else if (scale == 2) {
-            if (dpi < 192.) {
+            if (dpi < baseHiDPI) {
                 dpi *= 2.;
             }
         }
diff --git a/rtgui/rtscalable.h b/rtgui/rtscalable.h
index a932038f2..c3ff19e60 100644
--- a/rtgui/rtscalable.h
+++ b/rtgui/rtscalable.h
@@ -38,6 +38,15 @@ protected:
 
 
 public:
+
+#ifdef __APPLE__
+    static constexpr double baseDPI = 72;
+    static constexpr double baseHiDPI = 144;
+#else
+    static constexpr double baseDPI = 96;
+    static constexpr double baseHiDPI = 192;
+#endif
+
     static void init(Gtk::Window *window);
     static void cleanup();
     static double getDPI ();
diff --git a/rtgui/rtwindow.cc b/rtgui/rtwindow.cc
index 6a7b178b0..a79209a36 100644
--- a/rtgui/rtwindow.cc
+++ b/rtgui/rtwindow.cc
@@ -188,14 +188,14 @@ RTWindow::RTWindow ()
                 if (isPix) {
                     // HOMBRE: guessing here...
                     // if resolution is lower than 192ppi, we're supposing that it's already expressed in a scale==1 scenario
-                    if (resolution >= 192) {
+                    if (resolution >= int(RTScalable::baseHiDPI)) {
                         // converting the resolution to a scale==1 scenario
                         resolution /= 2;
                     }
                     // 1pt =  1/72in @ 96 ppi
                     // HOMBRE: If the font unit is px, is it alredy scaled up to match the resolution ?
                     //             px         >inch >pt      >"scaled pt"
-                    pt = (int)(fontSize / 96. * 72 * (96. / resolution) + 0.49);
+                    pt = (int)(double(fontSize) / RTScalable::baseDPI * 72. * (RTScalable::baseHiDPI / resolution) + 0.49);
                 } else {
                     pt = fontSize / Pango::SCALE;
                 }