diff --git a/include/ddk/ntddk.h b/include/ddk/ntddk.h
index 56f2f35a543..e9c3fbadd2d 100644
--- a/include/ddk/ntddk.h
+++ b/include/ddk/ntddk.h
@@ -140,6 +140,15 @@ typedef struct _FILE_VALID_DATA_LENGTH_INFORMATION
   LARGE_INTEGER ValidDataLength;
 } FILE_VALID_DATA_LENGTH_INFORMATION, *PFILE_VALID_DATA_LENGTH_INFORMATION;
 
+typedef struct _KWAIT_BLOCK {
+    LIST_ENTRY WaitListEntry;
+    struct _KTHREAD *RESTRICTED_POINTER Thread;
+    PVOID Object;
+    struct _KWAIT_BLOCK *RESTRICTED_POINTER NextWaitBlock;
+    USHORT WaitKey;
+    USHORT WaitType;
+} KWAIT_BLOCK, *PKWAIT_BLOCK, *RESTRICTED_POINTER PRKWAIT_BLOCK;
+
 typedef VOID (WINAPI *PDRIVER_NOTIFICATION_CALLBACK_ROUTINE)(PVOID,PVOID);
 typedef VOID (WINAPI *PDRIVER_REINITIALIZE)(PDRIVER_OBJECT,PVOID,ULONG);
 typedef VOID (WINAPI *PLOAD_IMAGE_NOTIFY_ROUTINE)(PUNICODE_STRING,HANDLE,PIMAGE_INFO);