diff --git a/src/cairoint.h b/src/cairoint.h
index fd6fc9aa4..4dbb7f917 100644
--- a/src/cairoint.h
+++ b/src/cairoint.h
@@ -1912,7 +1912,7 @@ cairo_private int
 _cairo_ucs4_to_utf16 (uint32_t    unicode,
 		      uint16_t   *utf16);
 
-#if CAIRO_HAS_WIN32_FONT || CAIRO_HAS_QUARTZ_FONT || CAIRO_HAS_PDF_OPERATORS
+#if _WIN32 || CAIRO_HAS_WIN32_FONT || CAIRO_HAS_QUARTZ_FONT || CAIRO_HAS_PDF_OPERATORS
 # define CAIRO_HAS_UTF8_TO_UTF16 1
 #endif
 #if CAIRO_HAS_UTF8_TO_UTF16