diff --git a/src/hb-ot-layout-gpos-table.hh b/src/hb-ot-layout-gpos-table.hh
index 8fe987fc5..f99f86a2a 100644
--- a/src/hb-ot-layout-gpos-table.hh
+++ b/src/hb-ot-layout-gpos-table.hh
@@ -56,12 +56,20 @@ PosLookup::dispatch_recurse_func<hb_closure_lookups_context_t> (hb_closure_looku
 template <>
 inline bool PosLookup::dispatch_recurse_func<hb_ot_apply_context_t> (hb_ot_apply_context_t *c, unsigned int lookup_index)
 {
-  const PosLookup &l = c->face->table.GPOS.get_relaxed ()->table->get_lookup (lookup_index);
+  auto *gpos = c->face->table.GPOS.get_relaxed ();
+  const PosLookup &l = gpos->table->get_lookup (lookup_index);
   unsigned int saved_lookup_props = c->lookup_props;
   unsigned int saved_lookup_index = c->lookup_index;
   c->set_lookup_index (lookup_index);
   c->set_lookup_props (l.get_props ());
-  bool ret = l.dispatch (c);
+
+  bool ret = false;
+  if (lookup_index < gpos->lookup_count)
+  {
+    auto &accel = gpos->accels[lookup_index];
+    ret = accel.apply (c, false);
+  }
+
   c->set_lookup_index (saved_lookup_index);
   c->set_lookup_props (saved_lookup_props);
   return ret;
diff --git a/src/hb-ot-layout-gsub-table.hh b/src/hb-ot-layout-gsub-table.hh
index 50301ff1d..418116126 100644
--- a/src/hb-ot-layout-gsub-table.hh
+++ b/src/hb-ot-layout-gsub-table.hh
@@ -69,12 +69,20 @@ SubstLookup::dispatch_recurse_func<hb_closure_lookups_context_t> (hb_closure_loo
 template <>
 inline bool SubstLookup::dispatch_recurse_func<hb_ot_apply_context_t> (hb_ot_apply_context_t *c, unsigned int lookup_index)
 {
-  const SubstLookup &l = c->face->table.GSUB.get_relaxed ()->table->get_lookup (lookup_index);
+  auto *gsub = c->face->table.GSUB.get_relaxed ();
+  const SubstLookup &l = gsub->table->get_lookup (lookup_index);
   unsigned int saved_lookup_props = c->lookup_props;
   unsigned int saved_lookup_index = c->lookup_index;
   c->set_lookup_index (lookup_index);
   c->set_lookup_props (l.get_props ());
-  bool ret = l.dispatch (c);
+
+  bool ret = false;
+  if (lookup_index < gsub->lookup_count)
+  {
+    auto &accel = gsub->accels[lookup_index];
+    ret = accel.apply (c, false);
+  }
+
   c->set_lookup_index (saved_lookup_index);
   c->set_lookup_props (saved_lookup_props);
   return ret;