diff --git a/src/hb-aat-layout-common.hh b/src/hb-aat-layout-common.hh
index 37d919a17..5db0d1212 100644
--- a/src/hb-aat-layout-common.hh
+++ b/src/hb-aat-layout-common.hh
@@ -40,8 +40,6 @@ namespace AAT {
 
 using namespace OT;
 
-#define HB_AAT_BUFFER_DIGEST_THRESHOLD 32
-
 struct ankr;
 
 using hb_aat_class_cache_t = hb_cache_t<15, 8, 7>;
diff --git a/src/hb-aat-layout-kerx-table.hh b/src/hb-aat-layout-kerx-table.hh
index 72d696212..d5f46c66e 100644
--- a/src/hb-aat-layout-kerx-table.hh
+++ b/src/hb-aat-layout-kerx-table.hh
@@ -967,10 +967,7 @@ struct KerxTable
   {
     c->buffer->unsafe_to_concat ();
 
-    if (c->buffer->len < HB_AAT_BUFFER_DIGEST_THRESHOLD)
-      c->buffer_digest = c->buffer->digest ();
-    else
-      c->buffer_digest = hb_set_digest_t::full ();
+    c->buffer_digest = c->buffer->digest ();
 
     typedef typename T::SubTable SubTable;
 
diff --git a/src/hb-aat-layout-morx-table.hh b/src/hb-aat-layout-morx-table.hh
index 1b836944e..65ad91303 100644
--- a/src/hb-aat-layout-morx-table.hh
+++ b/src/hb-aat-layout-morx-table.hh
@@ -1404,10 +1404,7 @@ struct mortmorx
 
     c->buffer->unsafe_to_concat ();
 
-    if (c->buffer->len < HB_AAT_BUFFER_DIGEST_THRESHOLD)
-      c->buffer_digest = c->buffer->digest ();
-    else
-      c->buffer_digest = hb_set_digest_t::full ();
+    c->buffer_digest = c->buffer->digest ();
 
     c->set_lookup_index (0);
     const Chain<Types> *chain = &firstChain;