diff --git a/cbcdes/sim/makefile b/cbcdes/sim/makefile
index 6b2c0e3..c58fc6e 100644
--- a/cbcdes/sim/makefile
+++ b/cbcdes/sim/makefile
@@ -30,7 +30,7 @@ sim : tb_cbcdes.ghw
 tb_cbcdes.ghw : ../rtl/*.vhd tb_cbcdes.vhd
 	ghdl -a ../rtl/des_pkg.vhd ../rtl/des.vhd ../rtl/cbcdes.vhd tb_cbcdes.vhd
 	ghdl -e tb_cbcdes
-	ghdl -r tb_cbcdes --wave=tb_cbcdes.ghw --assert-level=error --stop-time=30us
+	ghdl -r tb_cbcdes --wave=tb_cbcdes.ghw --assert-level=error --stop-time=100us
 	
 wave : tb_cbcdes.ghw
 	gtkwave tb_cbcdes.ghw