diff --git a/freeglut/freeglut/include/GL/freeglut_std.h b/freeglut/freeglut/include/GL/freeglut_std.h
index a658c7c..5ffc5a0 100644
--- a/freeglut/freeglut/include/GL/freeglut_std.h
+++ b/freeglut/freeglut/include/GL/freeglut_std.h
@@ -407,6 +407,13 @@
 #define  GLUT_GAME_MODE_REFRESH_RATE        0x0005
 #define  GLUT_GAME_MODE_DISPLAY_CHANGED     0x0006
 
+/*
+ * GLUT API macro definitions -- Spaceball button definitions
+ */
+
+#define  GLUT_SPACEBALL_BUTTON_A            0x0001
+#define  GLUT_SPACEBALL_BUTTON_B            0x0002
+
 /*
  * Initialization functions, see fglut_init.c
  */