diff --git a/reactos/drivers/wdm/audio/sysaudio/main.c b/reactos/drivers/wdm/audio/sysaudio/main.c
index 477ad98774f..7e8d692c9f0 100644
--- a/reactos/drivers/wdm/audio/sysaudio/main.c
+++ b/reactos/drivers/wdm/audio/sysaudio/main.c
@@ -9,6 +9,7 @@
  *                  8 Jul 07    Started basic implementation
  */
 
+#include <ntifs.h>
 #include <ntddk.h>
 #include <ks.h>
 #define YDEBUG
diff --git a/reactos/drivers/wdm/audio/sysaudio/sysaudio.h b/reactos/drivers/wdm/audio/sysaudio/sysaudio.h
index 31306606162..055739be4a7 100644
--- a/reactos/drivers/wdm/audio/sysaudio/sysaudio.h
+++ b/reactos/drivers/wdm/audio/sysaudio/sysaudio.h
@@ -23,13 +23,4 @@ typedef struct
     KMUTEX Mutex;
 }SYSAUDIODEVEXT;
 
-
-BOOLEAN
-NTAPI
-  RtlCreateUnicodeString(
-    OUT PUNICODE_STRING  DestinationString,
-    IN PCWSTR  SourceString
-    );
-
-
 #endif