diff --git a/src/common/image.cpp b/src/common/image.cpp
index 98037f9c39..0bf483822f 100644
--- a/src/common/image.cpp
+++ b/src/common/image.cpp
@@ -2185,6 +2185,8 @@ unsigned char *wxImage::GetAlpha() const
 
 void wxImage::InitAlpha()
 {
+    wxCHECK_RET( IsOk(), wxT("invalid image") );
+
     wxCHECK_RET( !HasAlpha(), wxT("image already has an alpha channel") );
 
     // initialize memory for alpha channel
diff --git a/src/msw/imaglist.cpp b/src/msw/imaglist.cpp
index c6ef84fd47..3e3a35762e 100644
--- a/src/msw/imaglist.cpp
+++ b/src/msw/imaglist.cpp
@@ -167,6 +167,12 @@ void
 wxImageList::GetImageListBitmaps(wxMSWBitmaps& bitmaps,
                                  const wxBitmap& bitmap, const wxBitmap& mask)
 {
+    if (!bitmap.IsOk())
+    {
+        // We can't do anything with an invalid bitmap.
+        return;
+    }
+
     // This can be overwritten below if we need to modify the bitmap, but it
     // doesn't cost anything to initialize the bitmap with this HBITMAP.
     bitmaps.hbmp = GetHbitmapOf(bitmap);