diff --git a/dlls/ntoskrnl.exe/ntoskrnl.c b/dlls/ntoskrnl.exe/ntoskrnl.c
index d1bdc336534..3013fe7eb90 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl.c
+++ b/dlls/ntoskrnl.exe/ntoskrnl.c
@@ -2196,6 +2196,7 @@ static void *create_process_object( HANDLE handle )
     process->header.Type = 3;
     process->header.WaitListHead.Blink = INVALID_HANDLE_VALUE; /* mark as kernel object */
     NtQueryInformationProcess( handle, ProcessBasicInformation, &process->info, sizeof(process->info), NULL );
+    IsWow64Process( handle, &process->wow64 );
     return process;
 }
 
@@ -3935,6 +3936,17 @@ PEPROCESS WINAPI IoGetRequestorProcess(IRP *irp)
     return irp->Tail.Overlay.Thread->kthread.process;
 }
 
+#ifdef _WIN64
+/***********************************************************************
+ *           IoIs32bitProcess   (NTOSKRNL.EXE.@)
+ */
+BOOLEAN WINAPI IoIs32bitProcess(IRP *irp)
+{
+    TRACE("irp %p.\n", irp);
+    return irp->Tail.Overlay.Thread->kthread.process->wow64;
+}
+#endif
+
 /***********************************************************************
  *           RtlIsNtDdiVersionAvailable   (NTOSKRNL.EXE.@)
  */
diff --git a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
index 14d95a47f85..8e3b127b164 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
+++ b/dlls/ntoskrnl.exe/ntoskrnl.exe.spec
@@ -416,6 +416,7 @@
 @ stdcall IoInitializeTimer(ptr ptr ptr)
 @ stdcall IoInvalidateDeviceRelations(ptr long)
 @ stub IoInvalidateDeviceState
+@ stdcall -arch=win64 IoIs32bitProcess(ptr)
 @ stub IoIsFileOriginRemote
 @ stub IoIsOperationSynchronous
 @ stub IoIsSystemThread
diff --git a/dlls/ntoskrnl.exe/ntoskrnl_private.h b/dlls/ntoskrnl.exe/ntoskrnl_private.h
index 256e945e6f3..23f03c336d5 100644
--- a/dlls/ntoskrnl.exe/ntoskrnl_private.h
+++ b/dlls/ntoskrnl.exe/ntoskrnl_private.h
@@ -40,6 +40,7 @@ struct _EPROCESS
 {
     DISPATCHER_HEADER header;
     PROCESS_BASIC_INFORMATION info;
+    BOOL wow64;
 };
 
 struct _KTHREAD
diff --git a/include/ddk/wdm.h b/include/ddk/wdm.h
index 60396779fc7..db8073ebe3d 100644
--- a/include/ddk/wdm.h
+++ b/include/ddk/wdm.h
@@ -1608,6 +1608,9 @@ void      WINAPI IoGetStackLimits(ULONG_PTR*,ULONG_PTR*);
 void      WINAPI IoInitializeIrp(IRP*,USHORT,CCHAR);
 VOID      WINAPI IoInitializeRemoveLockEx(PIO_REMOVE_LOCK,ULONG,ULONG,ULONG,ULONG);
 void      WINAPI IoInvalidateDeviceRelations(PDEVICE_OBJECT,DEVICE_RELATION_TYPE);
+#ifdef _WIN64
+BOOLEAN   WINAPI IoIs32bitProcess(IRP*);
+#endif
 NTSTATUS  WINAPI IoOpenDeviceRegistryKey(DEVICE_OBJECT*,ULONG,ACCESS_MASK,HANDLE*);
 void      WINAPI IoQueueWorkItem(PIO_WORKITEM,PIO_WORKITEM_ROUTINE,WORK_QUEUE_TYPE,void*);
 NTSTATUS  WINAPI IoRegisterDeviceInterface(PDEVICE_OBJECT,const GUID*,PUNICODE_STRING,PUNICODE_STRING);