diff --git a/common/rfb/PixelBuffer.h b/common/rfb/PixelBuffer.h
index 4a13923..fc35a7d 100644
--- a/common/rfb/PixelBuffer.h
+++ b/common/rfb/PixelBuffer.h
@@ -68,6 +68,7 @@
     //   The pointer is to the top-left pixel of the specified Rect.
     //   The buffer stride (in pixels) is returned.
     virtual const rdr::U8* getPixelsR(const Rect& r, int* stride) = 0;
+    virtual rdr::U8* getPixelsRW(const Rect& r, int* stride) = 0;
 
     // Get pixel data for a given part of the buffer
     //   Data is copied into the supplied buffer, with the specified
@@ -107,7 +108,7 @@
     virtual int getStride() const;
 
     // Get a pointer to specified pixel data
-    virtual rdr::U8* getPixelsRW(const Rect& r, int* stride);
+    rdr::U8* getPixelsRW(const Rect& r, int* stride);
     virtual const rdr::U8* getPixelsR(const Rect& r, int* stride) {
       return getPixelsRW(r, stride);
     }