diff --git a/docs/changes.txt b/docs/changes.txt
index f2b0cd09c1..b7880e5327 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -591,6 +591,7 @@ wxMSW:
 - Fix compilation with C++Builder XE compiler (Nichka).
 - Fix best height of wxSlider with labels but without ticks (Artur Wieczorek).
 - Fix initial text value of wxSpinCtrlDouble (Laurent Poujoulat).
+- Fix best size calculation for bitmaps with buttons (Artur Wieczorek).
 
 
 3.0.2: (released 2014-10-06)
diff --git a/src/msw/anybutton.cpp b/src/msw/anybutton.cpp
index b5d6dc84c0..2ee28d1e57 100644
--- a/src/msw/anybutton.cpp
+++ b/src/msw/anybutton.cpp
@@ -519,8 +519,9 @@ void wxAnyButton::AdjustForBitmapSize(wxSize &size) const
 {
     wxCHECK_RET( m_imageData, wxT("shouldn't be called if no image") );
 
-    // account for the bitmap size
-    const wxSize sizeBmp = m_imageData->GetBitmap(State_Normal).GetSize();
+    // account for the bitmap size, including the user-specified margins
+    const wxSize sizeBmp = m_imageData->GetBitmap(State_Normal).GetSize()
+                                + 2*m_imageData->GetBitmapMargins();
     const wxDirection dirBmp = m_imageData->GetBitmapPosition();
     if ( dirBmp == wxLEFT || dirBmp == wxRIGHT )
     {
@@ -535,9 +536,6 @@ void wxAnyButton::AdjustForBitmapSize(wxSize &size) const
             size.x = sizeBmp.x;
     }
 
-    // account for the user-specified margins
-    size += 2*m_imageData->GetBitmapMargins();
-
     // and also for the margins we always add internally (unless we have no
     // border at all in which case the button has exactly the same size as
     // bitmap and so no margins should be used)