diff --git a/src/xschem.tcl b/src/xschem.tcl
index 44ef502e..0a880a57 100644
--- a/src/xschem.tcl
+++ b/src/xschem.tcl
@@ -658,8 +658,20 @@ proc ev0 {args} {
 # should not be called directly by user 
 # does netlist post processing, called from global_(spice|vhdl|verilog)_netlist()
 proc netlist {source_file show netlist_file} {
- global XSCHEM_SHAREDIR flat_netlist netlist_dir
+ global XSCHEM_SHAREDIR flat_netlist netlist_dir simulate_bg
  global verilog_2001 debug_var OS verilog_bitblast
+
+
+
+ # if waves are loaded turn Waves button to yellow to indicate old waves are shown
+ set win_path [xschem get current_win_path]
+ set top_path [xschem get top_path]
+ set waves_var tctx::${win_path}_waves
+ set waves_button $top_path.menubar.waves
+ if {$waves_var ne $simulate_bg} {
+   set $waves_var yellow
+   $waves_button configure -bg yellow
+ }
  
  set netlist_type [xschem get netlist_type]
  if {$debug_var <= -1} { puts "netlist: source_file=$source_file, netlist_type=$netlist_type" }