diff --git a/sdk/xtdk/xtbase.h b/sdk/xtdk/xtbase.h
index 2598f0bb7..259dcfc47 100644
--- a/sdk/xtdk/xtbase.h
+++ b/sdk/xtdk/xtbase.h
@@ -99,14 +99,20 @@ typedef struct _M128
 /* Dispatcher object header structure definition */
 typedef struct _DISPATCHER_HEADER
 {
-    UCHAR Type;
     union
     {
-        UCHAR Absolute;
-        UCHAR NpxIrql;
+        struct
+        {
+            UCHAR Type;
+            UCHAR Absolute;
+            UCHAR Size;
+            union {
+                UCHAR Inserted;
+                BOOLEAN DebugActive;
+            };
+        };
+        VOLATILE LONG Lock;
     };
-    UCHAR Inserted;
-    BOOLEAN DebugActive;
     LONG SignalState;
     LIST_ENTRY WaitListHead;
 } DISPATCHER_HEADER, *PDISPATCHER_HEADER;
diff --git a/xtoskrnl/ke/kprocess.cc b/xtoskrnl/ke/kprocess.cc
index 8b16e7cc6..131aaac5d 100644
--- a/xtoskrnl/ke/kprocess.cc
+++ b/xtoskrnl/ke/kprocess.cc
@@ -127,6 +127,8 @@ KE::KProcess::InitializeProcess(IN OUT PKPROCESS Process,
                                 IN BOOLEAN Alignment)
 {
     /* Initialize process dispatcher header */
+    Process->Header.SignalState = 0;
+    Process->Header.Size = sizeof(KPROCESS) / sizeof(LONG);
     Process->Header.Type = ProcessObject;
 
     /* Initialize process wait list */