diff --git a/headers/private/graphics/neomagic/nm_macros.h b/headers/private/graphics/neomagic/nm_macros.h
index b9d475c7dd..9e27fb0063 100644
--- a/headers/private/graphics/neomagic/nm_macros.h
+++ b/headers/private/graphics/neomagic/nm_macros.h
@@ -172,6 +172,7 @@
 #define NMGRPHX_IFACECTRL1	0x10
 #define NMGRPHX_IFACECTRL2	0x11
 #define NMGRPHX_0x15		0x15
+#define NMGRPHX_ACT_CLK_SAV	0x19 /* >= NM2200? auto-pwr-save.. (b2-0) */
 #define NMGRPHX_PANELCTRL1	0x20
 #define NMGRPHX_PANELTYPE	0x21
 #define NMGRPHX_PANELCTRL2	0x25