diff --git a/Makefile b/Makefile
index 12c5a5e..bbc2f1a 100755
--- a/Makefile
+++ b/Makefile
@@ -2,6 +2,7 @@ DESTDIR   ?=
 PREFIX    ?= /usr/local
 MANPREFIX ?= $(PREFIX)/man
 CFLAGS += -Wall -Wextra
+CFLAGS += `pkg-config --cflags ncursesw 2>/dev/null || echo '-D_DEFAULT_SOURCE -D_XOPEN_SOURCE=600 -I/usr/include/ncursesw'`
 LDLIBS += `pkg-config --libs ncursesw 2>/dev/null || echo '-lcursesw -ltinfo'`
 torture: LDLIBS = -lm
 
diff --git a/ttyplot.c b/ttyplot.c
index 5c3c02e..f7bc556 100644
--- a/ttyplot.c
+++ b/ttyplot.c
@@ -5,7 +5,6 @@
 // Apache License 2.0
 //
 
-#define _XOPEN_SOURCE 500  // Get ncurses wchar_t support from SUSv2 (UNIX 98)
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>