diff --git a/src/univ/themes/win32.cpp b/src/univ/themes/win32.cpp
index 3261e10239..355244c890 100644
--- a/src/univ/themes/win32.cpp
+++ b/src/univ/themes/win32.cpp
@@ -3861,7 +3861,8 @@ bool wxWin32ScrollBarInputHandler::HandleMouse(wxInputConsumer *control,
     {
         // we just started dragging the thumb, remember its initial position to
         // be able to restore it if the drag is cancelled later
-        m_eventStartDrag = event;
+        m_eventStartDrag.m_x = event.m_x;
+        m_eventStartDrag.m_y = event.m_y;
     }
 
     return rc;
@@ -3956,7 +3957,8 @@ bool wxWin32ScrollBarInputHandler::HandleMouseMove(wxInputConsumer *control,
             {
                 // remember the current thumb position to be able to restore it
                 // if the mouse returns to it later
-                m_eventLastDrag = event;
+                m_eventLastDrag.m_x = event.m_x;
+                m_eventLastDrag.m_y = event.m_y;
 
                 // and restore the original position (before dragging) of the
                 // thumb for now