diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 337506419d9..152ca433b0e 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -8687,7 +8687,12 @@ vect_bb_slp_scalar_cost (vec_info *vinfo,
       ssa_op_iter op_iter;
       def_operand_p def_p;
 
-      if (!stmt_info || (*life)[i])
+      if (!stmt_info
+	  || (*life)[i]
+	  /* Defs also used in external nodes are not in the
+	     vectorized_scalar_stmts set as they need to be preserved.
+	     Honor that.  */
+	  || !vectorized_scalar_stmts.contains (stmt_info))
 	continue;
 
       stmt_vec_info orig_stmt_info = vect_orig_stmt (stmt_info);