diff --git a/reactos/include/ndk/rtlfuncs.h b/reactos/include/ndk/rtlfuncs.h
index d0b3118a0b9..21caee76379 100644
--- a/reactos/include/ndk/rtlfuncs.h
+++ b/reactos/include/ndk/rtlfuncs.h
@@ -660,7 +660,7 @@ RtlAddAccessAllowedAceEx(
     IN OUT PACL pAcl,
     IN ULONG dwAceRevision,
     IN ULONG AceFlags,
-    IN ULONG AccessMask,
+    IN ACCESS_MASK AccessMask,
     IN PSID pSid
 );
 
@@ -671,7 +671,7 @@ RtlAddAccessAllowedObjectAce(
     IN OUT PACL pAcl,
     IN ULONG dwAceRevision,
     IN ULONG AceFlags,
-    IN ULONG AccessMask,
+    IN ACCESS_MASK AccessMask,
     IN GUID *ObjectTypeGuid  OPTIONAL,
     IN GUID *InheritedObjectTypeGuid  OPTIONAL,
     IN PSID pSid
@@ -705,7 +705,7 @@ RtlAddAccessDeniedObjectAce(
     IN OUT PACL pAcl,
     IN ULONG dwAceRevision,
     IN ULONG AceFlags,
-    IN ULONG AccessMask,
+    IN ACCESS_MASK AccessMask,
     IN GUID *ObjectTypeGuid  OPTIONAL,
     IN GUID *InheritedObjectTypeGuid  OPTIONAL,
     IN PSID pSid