-buildarch := $(shell dpkg-architecture -qDEB_BUILD_ARCH)
-ifeq ($(buildarch),amd64)
-CFLAGS=-g -O2 -Wall -DUNALIGNED_OK
-else
-CFLAGS=-g -O2 -Wall
+CFLAGS = `dpkg-buildflags --get CFLAGS`
+CFLAGS += -Wall
+LDFLAGS = `dpkg-buildflags --get LDFLAGS`
+CPPFLAGS = `dpkg-buildflags --get CPPFLAGS`
+
+ifeq ($(shell dpkg-architecture -qDEB_HOST_ARCH),amd64)
+CFLAGS += -DUNALIGNED_OK