diff --git a/src/Makefile b/src/Makefile
index 70d7f02..c3506ee 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -55,16 +55,16 @@ deasm: $(deasm_OBJS) libasm.so
 	$(CC) -o deasm $(deasm_OBJS) $(deasm_LDFLAGS)
 
 arch.o: arch.c ../include/Asm/arch.h ../include/Asm/asm.h arch.h code.h ../config.h
-	$(CC) $(libasm_CFLAGS) -c arch.c
+	$(CC) -D PREFIX=\"$(PREFIX)\" $(libasm_CFLAGS) -c arch.c
 
 asm.o: asm.c ../include/Asm.h code.h parser.h ../config.h
-	$(CC) $(libasm_CFLAGS) -c asm.c
+	$(CC) -D PREFIX=\"$(PREFIX)\" $(libasm_CFLAGS) -c asm.c
 
 code.o: code.c ../include/Asm.h ../include/Asm/arch.h ../include/Asm/asm.h ../include/Asm/format.h arch.h code.h format.h ../config.h
-	$(CC) $(libasm_CFLAGS) -c code.c
+	$(CC) -D PREFIX=\"$(PREFIX)\" $(libasm_CFLAGS) -c code.c
 
 format.o: format.c ../include/Asm/asm.h ../include/Asm/format.h code.h format.h ../config.h
-	$(CC) $(libasm_CFLAGS) -c format.c
+	$(CC) -D PREFIX=\"$(PREFIX)\" $(libasm_CFLAGS) -c format.c
 
 parser.o: parser.c parser.h token.h
 	$(CC) $(libasm_CFLAGS) -c parser.c
diff --git a/src/project.conf b/src/project.conf
index f9135b5..f5e22c9 100644
--- a/src/project.conf
+++ b/src/project.conf
@@ -35,18 +35,22 @@ install=$(BINDIR)
 
 [arch.c]
 depends=../include/Asm/arch.h,../include/Asm/asm.h,arch.h,code.h,../config.h
+cppflags=-D PREFIX=\"$(PREFIX)\"
 
 [asm.c]
 depends=../include/Asm.h,code.h,parser.h,../config.h
+cppflags=-D PREFIX=\"$(PREFIX)\"
 
 [code.c]
 depends=../include/Asm.h,../include/Asm/arch.h,../include/Asm/asm.h,../include/Asm/format.h,arch.h,code.h,format.h,../config.h
+cppflags=-D PREFIX=\"$(PREFIX)\"
 
 [deasm.c]
 depends=../include/Asm.h,../include/Asm/arch.h,../include/Asm/asm.h,../include/Asm/format.h
 
 [format.c]
 depends=../include/Asm/asm.h,../include/Asm/format.h,code.h,format.h,../config.h
+cppflags=-D PREFIX=\"$(PREFIX)\"
 
 [main.c]
 depends=../include/Asm/asm.h,../config.h