1 files changed, 1 insertions, 1 deletions
diff --git a/Makefile b/Makefile
index d60e9d4..63cdcc4 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 VERSION = 0.2
 DESTDIR ?= /usr/local
-CFLAGS += -std=c99 -g -Wall -Wextra -DVERSION=\"${VERSION}\" -D_GNU_SOURCE
+CFLAGS += -std=c99 -g -Wall -Wextra -DVERSION=\"${VERSION}\" -D_POSIX_C_SOURCE=200809L
 MODE ?= 4711
 
 all: brightnessctl