diff --git a/Makefile b/Makefile
index d7e7f091c2..20e9c7bd0d 100644
--- a/Makefile
+++ b/Makefile
@@ -148,6 +148,8 @@ ifeq ($(DISTRO),ubuntu)
     SETUP_INSTALL_ARGS += --install-layout=deb
 endif
 
+CFLAGS ?=
+
 .DEFAULT_GOAL := build
 
 .PHONY: clean rebase push requirements requirements_dev requirements_jenkins \