diff --git a/src/hb-buffer.hh b/src/hb-buffer.hh
index 1d47a71a7..8635ebd35 100644
--- a/src/hb-buffer.hh
+++ b/src/hb-buffer.hh
@@ -189,13 +189,10 @@ struct hb_buffer_t
   hb_glyph_info_t &prev ()      { return out_info[out_len ? out_len - 1 : 0]; }
   hb_glyph_info_t prev () const { return out_info[out_len ? out_len - 1 : 0]; }
 
-  HB_NODISCARD bool has_separate_output () const { return info != out_info; }
-
-
   HB_INTERNAL void reset ();
   HB_INTERNAL void clear ();
 
-  unsigned int backtrack_len () const { return have_output? out_len : idx; }
+  unsigned int backtrack_len () const { return have_output ? out_len : idx; }
   unsigned int lookahead_len () const { return len - idx; }
   unsigned int next_serial () { return serial++; }
 
diff --git a/src/hb-ot-layout.cc b/src/hb-ot-layout.cc
index cb428fba8..0454af206 100644
--- a/src/hb-ot-layout.cc
+++ b/src/hb-ot-layout.cc
@@ -1894,8 +1894,6 @@ apply_string (OT::hb_ot_apply_context_t *c,
 
     if (!Proxy::inplace)
       buffer->swap_buffers ();
-    else
-      assert (!buffer->has_separate_output ());
   }
   else
   {