diff --git a/Makefile b/Makefile
index 1755a9c..d043c80 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,8 @@ PACKAGE_BUGREPORT := https://github.com/kaniini/ifupdown-ng/issues/new
 
 INTERFACES_FILE := /etc/network/interfaces
 STATE_FILE := /run/ifstate
-CFLAGS := -ggdb3 -O2 -Wall -I. -DINTERFACES_FILE=\"${INTERFACES_FILE}\" -DSTATE_FILE=\"${STATE_FILE}\" -DPACKAGE_NAME=\"${PACKAGE_NAME}\" -DPACKAGE_VERSION=\"${PACKAGE_VERSION}\" -DPACKAGE_BUGREPORT=\"${PACKAGE_BUGREPORT}\"
+CFLAGS = -ggdb3 -O2 -Wall -Wextra
+CPPFLAGS = -I. -DINTERFACES_FILE=\"${INTERFACES_FILE}\" -DSTATE_FILE=\"${STATE_FILE}\" -DPACKAGE_NAME=\"${PACKAGE_NAME}\" -DPACKAGE_VERSION=\"${PACKAGE_VERSION}\" -DPACKAGE_BUGREPORT=\"${PACKAGE_BUGREPORT}\"
 
 
 LIBIFUPDOWN_SRC = \