diff --git a/libmpdemux/asf.h b/libmpdemux/asf.h
index 1f89edf7fb..1e6210e603 100644
--- a/libmpdemux/asf.h
+++ b/libmpdemux/asf.h
@@ -6,20 +6,6 @@
 #include "libavutil/common.h"
 #include "mpbswap.h"
 
-///////////////////////
-// MS GUID definition
-///////////////////////
-#ifndef GUID_DEFINED
-#define GUID_DEFINED
-// Size of GUID is 16 bytes!
-typedef struct __attribute__((packed)) {
-	uint32_t	Data1;		// 4 bytes
-	uint16_t	Data2;		// 2 bytes
-	uint16_t	Data3;		// 2 bytes
-	uint8_t		Data4[8];	// 8 bytes
-} GUID_t;
-#endif
-
 ///////////////////////
 // ASF Object Header 
 ///////////////////////