diff --git a/src/hb-common.cc b/src/hb-common.cc
index 0ae0c05f4..5b8927a8a 100644
--- a/src/hb-common.cc
+++ b/src/hb-common.cc
@@ -69,7 +69,6 @@ _hb_options_init ()
 	if (0 == strncmp (c, name, p - c) && strlen (name) == static_cast<size_t>(p - c)) do { u.opts.symbol = true; } while (0)
 
       OPTION ("uniscribe-bug-compatible", uniscribe_bug_compatible);
-      OPTION ("aat", aat);
 
 #undef OPTION
 
diff --git a/src/hb-debug.hh b/src/hb-debug.hh
index a7e52c8cb..bd807f641 100644
--- a/src/hb-debug.hh
+++ b/src/hb-debug.hh
@@ -46,7 +46,6 @@ struct hb_options_t
   bool unused : 1; /* In-case sign bit is here. */
   bool initialized : 1;
   bool uniscribe_bug_compatible : 1;
-  bool aat : 1;
 };
 
 union hb_options_union_t {
diff --git a/src/hb-ot-layout.cc b/src/hb-ot-layout.cc
index ac6551b6b..cfc41df9f 100644
--- a/src/hb-ot-layout.cc
+++ b/src/hb-ot-layout.cc
@@ -399,27 +399,6 @@ OT::GSUB::is_blacklisted (hb_blob_t *blob HB_UNUSED,
 #ifdef HB_NO_OT_LAYOUT_BLACKLIST
   return false;
 #endif
-
-#ifndef HB_NO_AAT_SHAPE
-  /* Mac OS X prefers morx over GSUB.  It also ships with various Indic fonts,
-   * all by 'MUTF' foundry (Tamil MN, Tamil Sangam MN, etc.), that have broken
-   * GSUB/GPOS tables.  Some have GSUB with zero scripts, those are ignored by
-   * our morx/GSUB preference code.  But if GSUB has non-zero scripts, we tend
-   * to prefer it over morx because we want to be consistent with other OpenType
-   * shapers.
-   *
-   * To work around broken Indic Mac system fonts, we ignore GSUB table if
-   * OS/2 VendorId is 'MUTF' and font has morx table as well.
-   *
-   * https://github.com/harfbuzz/harfbuzz/issues/1410
-   * https://github.com/harfbuzz/harfbuzz/issues/1348
-   * https://github.com/harfbuzz/harfbuzz/issues/1391
-   */
-  if (unlikely (face->table.OS2->achVendID == HB_TAG ('M','U','T','F') &&
-		face->table.morx->has_data ()))
-    return true;
-#endif
-
   return false;
 }
 
diff --git a/src/hb-ot-shape.cc b/src/hb-ot-shape.cc
index 77358e57e..b8bd12f0f 100644
--- a/src/hb-ot-shape.cc
+++ b/src/hb-ot-shape.cc
@@ -63,23 +63,6 @@ hb_ot_shape_collect_features (hb_ot_shape_planner_t          *planner,
 			      const hb_feature_t             *user_features,
 			      unsigned int                    num_user_features);
 
-#ifndef HB_NO_AAT_SHAPE
-static inline bool
-_hb_apply_morx (hb_face_t *face)
-{
-  if (hb_options ().aat &&
-      hb_aat_layout_has_substitution (face))
-    return true;
-
-  /* Ignore empty GSUB tables. */
-  return (!hb_ot_layout_has_substitution (face) ||
-	  !hb_ot_layout_table_get_script_tags (face,
-					       HB_OT_TAG_GSUB,
-					       0, nullptr, nullptr)) &&
-	 hb_aat_layout_has_substitution (face);
-}
-#endif
-
 hb_ot_shape_planner_t::hb_ot_shape_planner_t (hb_face_t                     *face,
 					      const hb_segment_properties_t *props) :
 						face (face),
@@ -87,7 +70,7 @@ hb_ot_shape_planner_t::hb_ot_shape_planner_t (hb_face_t                     *fac
 						map (face, props),
 						aat_map (face, props)
 #ifndef HB_NO_AAT_SHAPE
-						, apply_morx (_hb_apply_morx (face))
+						, apply_morx (hb_aat_layout_has_substitution (face))
 #endif
 {
   shaper = hb_ot_shape_complex_categorize (this);
@@ -156,15 +139,11 @@ hb_ot_shape_planner_t::compile (hb_ot_shape_plan_t           &plan,
   if (0)
     ;
 #ifndef HB_NO_AAT_SHAPE
-  else if (hb_options ().aat && hb_aat_layout_has_positioning (face))
+  else if (hb_aat_layout_has_positioning (face))
     plan.apply_kerx = true;
 #endif
   else if (!apply_morx && !disable_gpos && hb_ot_layout_has_positioning (face))
     plan.apply_gpos = true;
-#ifndef HB_NO_AAT_SHAPE
-  else if (hb_aat_layout_has_positioning (face))
-    plan.apply_kerx = true;
-#endif
 
   if (!plan.apply_kerx && (!has_gpos_kern || !plan.apply_gpos))
   {