diff --git a/include/ksmedia.h b/include/ksmedia.h
index 35d23bdc218..5ca78f157b3 100644
--- a/include/ksmedia.h
+++ b/include/ksmedia.h
@@ -24,5 +24,6 @@
 #define _KSMEDIA_
 
 DEFINE_GUID(KSDATAFORMAT_SUBTYPE_PCM, 0x00000001, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71);
+DEFINE_GUID(KSDATAFORMAT_SUBTYPE_IEEE_FLOAT, 0x00000003, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71);
 
 #endif  /* _KSMEDIA_ */