diff --git a/src/locale/haiku/SDL_syslocale.cc b/src/locale/haiku/SDL_syslocale.cc
index 44cae7a55..a0885fa42 100644
--- a/src/locale/haiku/SDL_syslocale.cc
+++ b/src/locale/haiku/SDL_syslocale.cc
@@ -20,6 +20,7 @@
 */
 
 #include <LocaleRoster.h>
+#include <TypeConstants.h>
 
 #include "../../SDL_internal.h"
 #include "../SDL_syslocale.h"