diff --git a/src/unix/uiactionx11.cpp b/src/unix/uiactionx11.cpp
index 56af15ebef..4bf33c93b0 100644
--- a/src/unix/uiactionx11.cpp
+++ b/src/unix/uiactionx11.cpp
@@ -27,6 +27,11 @@
 
 #include "wx/unix/utilsx11.h"
 
+#ifdef __WXGTK3__
+#include <gdk/gdk.h>
+#include <gtk/gtk.h>
+#endif
+
 // Normally we fall back on "plain X" implementation if XTest is not available,
 // but it's useless to do it when using GTK+ 3 as it's not going to work with
 // it anyhow because GTK+ 3 needs XInput2 events and not the "classic" ones we
@@ -239,6 +244,27 @@ bool wxUIActionSimulatorXTestImpl::DoX11Button(int xbutton, bool isDown)
 
 bool wxUIActionSimulatorXTestImpl::DoX11MouseMove(long x, long y)
 {
+#ifdef __WXGTK3__
+    // We need to take into account the scaling factor as the input coordinates
+    // are in GTK logical "application pixels", while we need the physical
+    // "device pixels" for the X call below, so scale them if we have the
+    // required support at both compile- and run-time.
+#if GTK_CHECK_VERSION(3,10,0)
+    if ( gtk_check_version(3, 10, 0) == NULL )
+    {
+        if ( GdkScreen* const screen = gdk_screen_get_default() )
+        {
+            // For multi-monitor support we would need to determine to which
+            // monitor the point (x, y) belongs, for now just use the scale
+            // factor of the main one.
+            gint const scale = gdk_screen_get_monitor_scale_factor(screen, 0);
+            x *= scale;
+            y *= scale;
+        }
+    }
+#endif // GTK+ 3.10+
+#endif // __WXGTK3__
+
     return XTestFakeMotionEvent(m_display, -1, x, y, 0) != 0;
 }