diff --git a/headers/private/graphics/nvidia/DriverInterface.h b/headers/private/graphics/nvidia/DriverInterface.h
index 6f8e3dbfed..793410debb 100644
--- a/headers/private/graphics/nvidia/DriverInterface.h
+++ b/headers/private/graphics/nvidia/DriverInterface.h
@@ -67,7 +67,9 @@ enum {
 	NV_DEVICE_NAME,
 	NV_RUN_INTERRUPTS,
 	NV_GET_NTH_AGP_INFO,
-	NV_ENABLE_AGP
+	NV_ENABLE_AGP,
+	NV_ISA_OUT,
+	NV_ISA_IN
 };
 
 /* max. number of overlay buffers */
@@ -341,6 +343,14 @@ typedef struct {
 	uint32		cmd;	/* actual command to execute */
 } nv_cmd_agp;
 
+/* Read or write a value in ISA I/O space */
+typedef struct {
+	uint32	magic;		/* magic number to make sure the caller groks us */
+	uint16	adress;		/* Offset to read/write */
+	uint8	size;		/* Number of bytes to transfer */
+	uint16	data;		/* The value read or written */
+} nv_in_out_isa;
+
 enum {
 	
 	_WAIT_FOR_VBLANK = (1 << 0)