1 files changed, 1 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 8e6676c..13fa0ea 100644
--- a/Makefile
+++ b/Makefile
@@ -46,7 +46,7 @@ CONFIG_TRE ?= 0
 CONFIG_ACL ?= 0
 CONFIG_SELINUX ?= 0
 
-CFLAGS_STD ?= -std=c99 -D_POSIX_C_SOURCE=200809L -D_XOPEN_SOURCE=700 -DNDEBUG -MMD
+CFLAGS_STD ?= -std=c99 -U_XOPEN_SOURCE -D_XOPEN_SOURCE=700 -DNDEBUG -MMD
 CFLAGS_STD += -DVERSION=\"${VERSION}\"
 LDFLAGS_STD ?= -lc