diff --git a/docs/changes.txt b/docs/changes.txt
index c4a73d2224..e364cd20cf 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -229,6 +229,7 @@ wxMSW:
   hotkey
 - fix for multiple consecutive groups of radiobuttons
 - fix for incorrect display of tooltips in non English locales (Niki Spahiev)
+- fixed memory leak when setting new wxMask for wxBitmap
 
 wxMotif:
 
diff --git a/src/msw/bitmap.cpp b/src/msw/bitmap.cpp
index 038afaa721..433a4ff392 100644
--- a/src/msw/bitmap.cpp
+++ b/src/msw/bitmap.cpp
@@ -1088,6 +1088,7 @@ void wxBitmap::SetMask(wxMask *mask)
 {
     EnsureHasData();
 
+    delete GetBitmapData()->m_bitmapMask ;
     GetBitmapData()->m_bitmapMask = mask;
 }