diff --git a/src/hb-unicode-private.hh b/src/hb-unicode-private.hh
index cd6c67c87..eaa12d8f7 100644
--- a/src/hb-unicode-private.hh
+++ b/src/hb-unicode-private.hh
@@ -105,10 +105,6 @@ HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS_SIMPLE
   inline unsigned int
   modified_combining_class (hb_codepoint_t unicode)
   {
-    /* XXX This hack belongs to the Arabic shaper:
-     * Put HAMZA ABOVE in the same class as SHADDA. */
-    if (unlikely (unicode == 0x0654u)) unicode = 0x0651u;
-
     /* XXX This hack belongs to the Myanmar shaper. */
     if (unlikely (unicode == 0x1037u)) unicode = 0x103Au;