1 files changed, 1 insertions, 1 deletions
diff --git a/Makefile b/Makefile
index f8f5ba4..54ba350 100644
--- a/Makefile
+++ b/Makefile
@@ -11,7 +11,7 @@ DOCPREFIX = ${PREFIX}/share/doc/${NAME}
 # use system flags.
 TABBED_CFLAGS = -I/usr/X11R6/include -I/usr/include/freetype2 ${CFLAGS}
 TABBED_LDFLAGS = -L/usr/X11R6/lib -lX11 -lfontconfig -lXft ${LDFLAGS}
-TABBED_CPPFLAGS = -DVERSION=\"${VERSION}\" -D_DEFAULT_SOURCE
+TABBED_CPPFLAGS = -DVERSION=\"${VERSION}\" -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=700L
 
 # OpenBSD (uncomment)
 #TABBED_CFLAGS = -I/usr/X11R6/include -I/usr/X11R6/include/freetype2 ${CFLAGS}