diff --git a/Makefile b/Makefile
index 47594bb..4af8e92 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 OBJS = dpflib.o rawusb.o scsi.o bootload.o
 
-CFLAGS = -Wall -fPIC -I../include -g
+CFLAGS = -Wall -fPIC -I$(PREFIX)/include -I../include -g
 # CFLAGS += -DDEBUG
 
 ifndef DESTDIR