diff --git a/MagickCore/method-attribute.h b/MagickCore/method-attribute.h
index 1d980d4..e8e30fc 100644
--- a/MagickCore/method-attribute.h
+++ b/MagickCore/method-attribute.h
@@ -112,14 +112,17 @@
 #  define magick_aligned(x,y)  x __attribute__((aligned(y)))
 #  define magick_attribute  __attribute__
 #  define magick_unused(x)  magick_unused_ ## x __attribute__((unused))
+#  define magick_unreferenced(x)  /* nothing */
 #elif defined(MAGICKCORE_WINDOWS_SUPPORT) && !defined(__CYGWIN__)
 #  define magick_aligned(x,y)  __declspec(align(y)) x
 #  define magick_attribute(x)  /* nothing */
 #  define magick_unused(x) x
+#  define magick_unreferenced(x) (x)
 #else
 #  define magick_aligned(x,y)  /* nothing */
 #  define magick_attribute(x)  /* nothing */
 #  define magick_unused(x) x
+#  define magick_unreferenced(x)  /* nothing */
 #endif
 
 #if (((__GNUC__) > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 3)))