diff --git a/reactos/include/ddk/ntifs.h b/reactos/include/ddk/ntifs.h
index 30ec249b11f..365969c1561 100644
--- a/reactos/include/ddk/ntifs.h
+++ b/reactos/include/ddk/ntifs.h
@@ -3061,13 +3061,6 @@ HalDisplayString (
     IN PCHAR String
 );
 
-NTHALAPI
-VOID
-NTAPI
-HalSetRealTimeClock (
-    IN PTIME_FIELDS TimeFields
-);
-
 NTKERNELAPI
 NTSTATUS
 NTAPI
diff --git a/reactos/include/ndk/obfuncs.h b/reactos/include/ndk/obfuncs.h
index e9741369ccb..eb9970e6495 100644
--- a/reactos/include/ndk/obfuncs.h
+++ b/reactos/include/ndk/obfuncs.h
@@ -23,6 +23,7 @@ Author:
 // Dependencies
 //
 #include <umtypes.h>
+#include <obtypes.h>
 
 #ifndef NTOS_MODE_USER
 
diff --git a/reactos/include/reactos/arc/arc.h b/reactos/include/reactos/arc/arc.h
index 19affe8b043..72a8afb3386 100644
--- a/reactos/include/reactos/arc/arc.h
+++ b/reactos/include/reactos/arc/arc.h
@@ -1,6 +1,35 @@
 #ifndef _ARC_
 #define _ARC_
 
+typedef ULONG ARC_STATUS;
+
+typedef enum _ARC_CODES
+{
+    ESUCCESS,
+    E2BIG,
+    EACCES,
+    EAGAIN,
+    EBADF,
+    EBUSY,
+    EFAULT,
+    EINVAL,
+    EIO,
+    EISDIR,
+    EMFILE,
+    EMLINK,
+    ENAMETOOLONG,
+    ENODEV,
+    ENOENT,
+    ENOEXEC,
+    ENOMEM,
+    ENOSPC,
+    ENOTDIR,
+    ENOTTY,
+    ENXIO,
+    EROFS,
+    EMAXIMUM
+} ARC_CODES;
+
 typedef enum _IDENTIFIER_FLAG
 {
     Failed = 0x01,