diff --git a/meson.build b/meson.build
index 582f356209..fbdd415376 100644
--- a/meson.build
+++ b/meson.build
@@ -679,6 +679,9 @@ iconv = not_found
 curses = not_found
 if have_system and not get_option('curses').disabled()
   curses_test = '''
+    #if defined(__APPLE__) || defined(__OpenBSD__)
+    #define _XOPEN_SOURCE_EXTENDED 1
+    #endif
     #include <locale.h>
     #include <curses.h>
     #include <wchar.h>
@@ -702,7 +705,7 @@ if have_system and not get_option('curses').disabled()
     endif
   endforeach
   msg = get_option('curses').enabled() ? 'curses library not found' : ''
-  curses_compile_args = ['-DNCURSES_WIDECHAR']
+  curses_compile_args = ['-DNCURSES_WIDECHAR=1']
   if curses.found()
     if cc.links(curses_test, args: curses_compile_args, dependencies: [curses])
       curses = declare_dependency(compile_args: curses_compile_args, dependencies: [curses])
diff --git a/ui/curses.c b/ui/curses.c
index e4f9588c3e..861d63244c 100644
--- a/ui/curses.c
+++ b/ui/curses.c
@@ -38,6 +38,10 @@
 #include "ui/input.h"
 #include "sysemu/sysemu.h"
 
+#if defined(__APPLE__) || defined(__OpenBSD__)
+#define _XOPEN_SOURCE_EXTENDED 1
+#endif
+
 /* KEY_EVENT is defined in wincon.h and in curses.h. Avoid redefinition. */
 #undef KEY_EVENT
 #include <curses.h>