diff --git a/Makefile b/Makefile
index 4f7b62b..f32d3ba 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@ PREFIX=/usr/local
 BINDIR=$(PREFIX)/bin
 MANDIR=$(PREFIX)/share/man
 
-CFLAGS=-Wall -Werror -Wextra -Wpedantic -Wno-unused-parameter -Wconversion -Wformat-security -Wformat -Wsign-conversion -Wfloat-conversion -Wunused-result
+CFLAGS+=-Wall -Werror -Wextra -Wpedantic -Wno-unused-parameter -Wconversion -Wformat-security -Wformat -Wsign-conversion -Wfloat-conversion -Wunused-result
 LIBS=-lwayland-client
 OBJ=wlopm.o wlr-output-power-management-unstable-v1.o xdg-output-unstable-v1.o
 GEN=wlr-output-power-management-unstable-v1.c wlr-output-power-management-unstable-v1.h xdg-output-unstable-v1.c xdg-output-unstable-v1.h