diff --git a/software/bios/Makefile b/software/bios/Makefile
index 10cae9632..77f60c97f 100644
--- a/software/bios/Makefile
+++ b/software/bios/Makefile
@@ -24,6 +24,9 @@ bios-rescue.elf: linker-rescue.ld $(OBJECTS) libs
 		-lbase -lcompiler-rt
 	chmod -x $@
 
+main.o: main.c
+	$(compile-dep)
+
 %.o: %.c
 	$(compile-dep)
 
@@ -38,6 +41,6 @@ flash: bios.bin
 	m1nor bios.bin
 
 clean:
-	rm -f $(OBJECTS) $(OBJECTS:.o=.ts) $(OBJECTS:.o=.d) bios.elf bios.bin bios-rescue.elf bios-rescue.bin .*~ *~
+	rm -f $(OBJECTS) $(OBJECTS:.o=.d) bios.elf bios.bin bios-rescue.elf bios-rescue.bin .*~ *~
 
-.PHONY: clean libs flash
+.PHONY: main.o clean libs flash
diff --git a/software/bios/main.c b/software/bios/main.c
index 606ba8c6b..20ffd0d08 100644
--- a/software/bios/main.c
+++ b/software/bios/main.c
@@ -423,7 +423,8 @@ static void print_mac(void)
 
 static const char banner[] =
 	"\nMILKYMIST(tm) v"VERSION" BIOS   http://www.milkymist.org\n"
-	"(c) Copyright 2007-2012 Sebastien Bourdeauducq\n\n"
+	"(c) Copyright 2007-2013 Sebastien Bourdeauducq\n"
+	"Built "__DATE__" "__TIME__"\n\n"
 	"This program is free software: you can redistribute it and/or modify\n"
 	"it under the terms of the GNU General Public License as published by\n"
 	"the Free Software Foundation, version 3 of the License.\n";