diff --git a/lib/emac/sim/tb_emac_top_jb.fdo b/lib/emac/sim/tb_emac_top_jb.fdo
index dd1a10c..bbb3ced 100644
--- a/lib/emac/sim/tb_emac_top_jb.fdo
+++ b/lib/emac/sim/tb_emac_top_jb.fdo
@@ -1,6 +1,8 @@
 ## NOTE:  Do not edit this file.
 ## Autogenerated by ProjNav (creatfdo.tcl) on Thu Jul 06 20:49:07 Westeuropäische Sommerzeit 2006
 ##
+if {[file exists work]} {vdel -lib work -all}
+
 vlib work
 vcom -explicit  -93 "../../misc/utils_pkg.vhd"
 vcom -explicit  -93 "../../rams/dpram_1w1r2c_ra_sim.vhd"