diff --git a/common/rfb/Cursor.h b/common/rfb/Cursor.h
index 5d4623d..560e4d8 100644
--- a/common/rfb/Cursor.h
+++ b/common/rfb/Cursor.h
@@ -34,7 +34,7 @@
     rdr::U8Array mask;
     Point hotspot;
 
-    int maskLen() { return (width() + 7) / 8 * height(); }
+    int maskLen() const { return (width() + 7) / 8 * height(); }
 
     // setSize() resizes the cursor.  The contents of the data and mask are
     // undefined after this call.
@@ -46,7 +46,7 @@
     // getBitmap() tests whether the cursor is monochrome, and if so returns a
     // bitmap together with background and foreground colours.  The size and
     // layout of the bitmap are the same as the mask.
-    rdr::U8* getBitmap(Pixel* pix0, Pixel* pix1);
+    rdr::U8* getBitmap(Pixel* pix0, Pixel* pix1) const;
 
     // crop() crops the cursor down to the smallest possible size, based on the
     // mask.
@@ -59,7 +59,7 @@
 
     Rect getEffectiveRect() const { return buffer.getRect(offset); }
 
-    virtual const rdr::U8* getBuffer(const Rect& r, int* stride);
+    virtual const rdr::U8* getBuffer(const Rect& r, int* stride) const;
 
     void update(PixelBuffer* framebuffer, Cursor* cursor, const Point& pos);