diff --git a/tgt-vhdl/display.cc b/tgt-vhdl/display.cc
index c599aabc3..e70f1bce5 100644
--- a/tgt-vhdl/display.cc
+++ b/tgt-vhdl/display.cc
@@ -162,7 +162,7 @@ int draw_stask_display(vhdl_procedural *proc, stmt_container *container,
          }
          else {
             vhdl_expr *base = translate_expr(net);
-            if (NULL == base)
+            if (NULL == base) 
                return 1;
             
             display_write(container, base);
diff --git a/tgt-vhdl/expr.cc b/tgt-vhdl/expr.cc
index f0aec0019..007abb203 100644
--- a/tgt-vhdl/expr.cc
+++ b/tgt-vhdl/expr.cc
@@ -355,8 +355,10 @@ static vhdl_expr *translate_select(ivl_expr_t e)
 {
    vhdl_var_ref *from =
       dynamic_cast<vhdl_var_ref*>(translate_expr(ivl_expr_oper1(e)));
-   if (NULL == from)
+   if (NULL == from) {
+      error("Can only select from variable reference");
       return NULL;
+   }
 
    ivl_expr_t o2 = ivl_expr_oper2(e);
    if (o2) {
@@ -454,7 +456,7 @@ vhdl_expr *translate_expr(ivl_expr_t e)
 {
    assert(e);
    ivl_expr_type_t type = ivl_expr_type(e);
-
+   
    switch (type) {
    case IVL_EX_STRING:
       return translate_string(e);