--- a/Makefile
+++ b/Makefile
@@ -15,9 +15,9 @@
 endif
 
 LIBDIR := /lib
-INCLUDEDIR := /usr/include
-PKGCONFIGDIR := /usr/lib/pkgconfig
-CFLAGS := -ggdb3 -O2 -Wall
+INCLUDEDIR := /include
+PKGCONFIGDIR := /lib/pkgconfig
+CFLAGS ?= -ggdb3 -O2 -Wall
 CPPFLAGS := -Iinclude -Iarch/${ARCH} -Iarch/common
 EXPORT_UNPREFIXED := yes
 FREESTANDING := no