1 files changed, 4 insertions, 4 deletions

diff --git a/Makefile b/Makefile
index 52b10cc..522a7d5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,7 @@
 SOURCES := $(shell find hdl sim -name \*.sv -o -name \*.cpp)
 HEADERS := $(shell find hdl -name \*.svh)
 MEMORIES := $(shell find mem -name \*.hex)
+QUARTUS := $(shell find altera tcl -name \*.cdf -o -name \*.sdc -o -name \*.tcl)
 
 OPTS ?=
 
@@ -15,11 +16,10 @@ build/Vtop: $(SOURCES) $(HEADERS)
         @ln -t build -f verilator/Vtop
         @rm -rf verilator
 
-noncpu.qpf: $(SOURCES) $(HEADERS) $(MEMORIES)
+noncpu.sof: $(SOURCES) $(HEADERS) $(MEMORIES) $(QUARTUS)
+        [ ! -e noncpu.qpf ] || quartus_sh -t tcl/clean.tcl
         quartus_sh -t tcl/init.tcl
-
-noncpu.sof: noncpu.qpf $(SOURCES) $(HEADERS) $(MEMORIES)
-        quartus_sh --flow compile $<
+        quartus_sh --flow compile noncpu.qpf
 
 fpga: noncpu.sof
         quartus_pgm -c 1 -m JTAG -o "P;$<@1"