diff --git a/reactos/include/xdk/amd64/ke.h b/reactos/include/xdk/amd64/ke.h
index e72519dc98e..c863e71c551 100644
--- a/reactos/include/xdk/amd64/ke.h
+++ b/reactos/include/xdk/amd64/ke.h
@@ -73,7 +73,7 @@ FORCEINLINE
 VOID
 KeLowerIrql(IN KIRQL NewIrql)
 {
-  //ASSERT(KeGetCurrentIrql() >= NewIrql);
+  ASSERT((KIRQL)__readcr8() >= NewIrql);
   __writecr8(NewIrql);
 }
 
@@ -84,7 +84,7 @@ KfRaiseIrql(IN KIRQL NewIrql)
   KIRQL OldIrql;
 
   OldIrql = (KIRQL)__readcr8();
-  //ASSERT(OldIrql <= NewIrql);
+  ASSERT(OldIrql <= NewIrql);
   __writecr8(NewIrql);
   return OldIrql;
 }
diff --git a/reactos/include/xdk/ketypes.h b/reactos/include/xdk/ketypes.h
index 0508315f226..740ee737f7d 100644
--- a/reactos/include/xdk/ketypes.h
+++ b/reactos/include/xdk/ketypes.h
@@ -463,7 +463,11 @@ typedef struct _KWAIT_BLOCK {
   struct _KWAIT_BLOCK *NextWaitBlock;
   USHORT WaitKey;
   UCHAR WaitType;
+#if (NTDDI_VERSION >= NTDDI_LONGHORN)
   volatile UCHAR BlockState;
+#else
+  UCHAR SpareByte;
+#endif
 #if defined(_WIN64)
   LONG SpareLong;
 #endif