diff --git a/src/msw/spinctrl.cpp b/src/msw/spinctrl.cpp
index 8c50bfef6e..1b47c3e428 100644
--- a/src/msw/spinctrl.cpp
+++ b/src/msw/spinctrl.cpp
@@ -340,20 +340,23 @@ bool wxSpinCtrl::Create(wxWindow *parent,
     if (!m_hasFont)
         SetFont(GetDefaultAttributes().font);
 
-    // finally deal with the size, now that both windows are created and the
-    // font is set
-    const wxSize sizeBtn = wxSpinButton::DoGetBestSize();
+    // Finally deal with the size: notice that this can only be done now both
+    // windows are created and the text one is set up as buddy because
+    // UDM_SETBUDDY changes its size using some unknown algorithm, so setting
+    // the sizes earlier is useless.
+    const int bestSpinWidth = wxSpinButton::DoGetBestSize().x;
+    const int effectiveSpinWidth = bestSpinWidth - GetOverlap();
     wxSize sizeCtrl(size);
     if ( sizeCtrl.x <= 0 )
     {
         // DEFAULT_ITEM_WIDTH is the default width for the text control
-        sizeCtrl.x = FromDIP(DEFAULT_ITEM_WIDTH) + sizeBtn.x - GetOverlap();
+        sizeCtrl.x = FromDIP(DEFAULT_ITEM_WIDTH) + effectiveSpinWidth;
     }
-    else if ( sizeCtrl.x <= sizeBtn.x )
+    else if ( sizeCtrl.x <= effectiveSpinWidth )
     {
         wxLogDebug(wxS("wxSpinCtrl \"%s\": initial width %d is too small, ")
                    wxS("at least %d pixels needed."),
-                   name, size.x, sizeBtn.x);
+                   name, size.x, effectiveSpinWidth);
     }
 
     // adjust an invalid height for text control
@@ -365,6 +368,7 @@ bool wxSpinCtrl::Create(wxWindow *parent,
         sizeCtrl.y = EDIT_HEIGHT_FROM_CHAR_HEIGHT(cy);
     }
 
+    // This will call our DoMoveWindow() and lay out the windows correctly.
     SetInitialSize(sizeCtrl);
 
     (void)::ShowWindow(GetBuddyHwnd(), SW_SHOW);