2 files changed, 2 insertions, 2 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
 
diff --git a/configure b/configure
index 5d7c821..3f286a0 100755
--- a/configure
+++ b/configure
@@ -220,7 +220,7 @@ tryflag   CFLAGS_TRY  -Werror=unused-command-line-argument
 tryldflag LDFLAGS_TRY -Werror=unknown-warning-option
 tryldflag LDFLAGS_TRY -Werror=unused-command-line-argument
 
-CFLAGS_STD="-std=c99 -D_POSIX_C_SOURCE=200809L -U_XOPEN_SOURCE -D_XOPEN_SOURCE=700 -DNDEBUG -MMD"
+CFLAGS_STD="-std=c99 -U_XOPEN_SOURCE -D_XOPEN_SOURCE=700 -DNDEBUG -MMD"
 LDFLAGS_STD="-lc"
 
 OS=$(uname)