diff --git a/test/val/Makefile b/test/val/Makefile
index 1a9fa9a45..acac670cb 100644
--- a/test/val/Makefile
+++ b/test/val/Makefile
@@ -22,7 +22,7 @@ ifdef QUIET
   NULLERR = 2>$(NULLDEV)
 endif
 
-SIM65FLAGS = -x 5000000000
+SIM65FLAGS = -x 5000000000 -c
 
 CC65 := $(if $(wildcard ../../bin/cc65*),..$S..$Sbin$Scc65,cc65)
 CA65 := $(if $(wildcard ../../bin/ca65*),..$S..$Sbin$Sca65,ca65)
@@ -48,10 +48,10 @@ define PRG_template
 
 $(WORKDIR)/%.$1.$2.prg: %.c | $(WORKDIR)
 	$(if $(QUIET),echo val/$$*.$1.$2.prg)
-	$(CC65) -t sim$2 $$(CC65FLAGS) -$1 -o $$(@:.prg=.s) $$< $(NULLERR)
+	$(CC65) -t sim$2 $$(CC65FLAGS) --add-source -$1 -o $$(@:.prg=.s) $$< $(NULLERR)
 	$(CA65) -t sim$2 -o $$(@:.prg=.o) $$(@:.prg=.s) $(NULLERR)
 	$(LD65) -t sim$2 -o $$@ $$(@:.prg=.o) sim$2.lib $(NULLERR)
-	$(SIM65) $(SIM65FLAGS) $$@ $(NULLOUT)
+	$(SIM65) $(SIM65FLAGS) $$@ > $(WORKDIR)/$$@.out
 
 endef # PRG_template