--- Makefile.orig	2026-02-20 11:56:18 UTC
+++ Makefile
@@ -1,6 +1,6 @@ CPPFLAGS=-g -Wall -Wextra -DWITH_XCB=$(xcb) -Werror
 xcb?=1
 CPPFLAGS=-g -Wall -Wextra -DWITH_XCB=$(xcb) -Werror
-CFLAGS=-std=c99
+CFLAGS+=-std=c99
 LDLIBS=-lm -lX11 -lXrandr -lXinerama
 
 LDLIBS_xcb1=-lxcb -lxcb-randr -lxcb-xinerama -lxcb-xrm