diff --git a/ntoskrnl/se/sid.c b/ntoskrnl/se/sid.c
index 557447f539f..033d322d708 100644
--- a/ntoskrnl/se/sid.c
+++ b/ntoskrnl/se/sid.c
@@ -580,51 +580,41 @@ SepGetSidFromAce(
     _In_ UCHAR AceType,
     _In_ PACE Ace)
 {
-    PSID Sid;
+    PULONG Flags;
+    ULONG GuidSize = 0;
+    PSID Sid = NULL;
     PAGED_CODE();
 
     /* Sanity check */
     ASSERT(Ace);
 
-    /* Initialize the SID */
-    Sid = NULL;
-
     /* Obtain the SID based upon ACE type */
     switch (AceType)
     {
         case ACCESS_DENIED_ACE_TYPE:
-        {
-            Sid = (PSID)&((PACCESS_DENIED_ACE)Ace)->SidStart;
-            break;
-        }
-
         case ACCESS_ALLOWED_ACE_TYPE:
+        case SYSTEM_AUDIT_ACE_TYPE:
+        case SYSTEM_ALARM_ACE_TYPE:
         {
-            Sid = (PSID)&((PACCESS_ALLOWED_ACE)Ace)->SidStart;
+            Sid = (PSID)&((PKNOWN_ACE)Ace)->SidStart;
             break;
         }
 
         case ACCESS_DENIED_OBJECT_ACE_TYPE:
-        {
-            Sid = (PSID)&((PACCESS_DENIED_OBJECT_ACE)Ace)->SidStart;
-            break;
-        }
-
         case ACCESS_ALLOWED_OBJECT_ACE_TYPE:
         {
-            Sid = (PSID)&((PACCESS_ALLOWED_OBJECT_ACE)Ace)->SidStart;
-            break;
-        }
+            Flags = (PULONG)&((PKNOWN_OBJECT_ACE)Ace)->Flags;
+            if (*Flags & ACE_OBJECT_TYPE_PRESENT)
+            {
+                GuidSize += sizeof(GUID);
+            }
 
-        case SYSTEM_AUDIT_ACE_TYPE:
-        {
-            Sid = (PSID)&((PSYSTEM_AUDIT_ACE)Ace)->SidStart;
-            break;
-        }
+            if (*Flags & ACE_INHERITED_OBJECT_TYPE_PRESENT)
+            {
+                GuidSize += sizeof(GUID);
+            }
 
-        case SYSTEM_ALARM_ACE_TYPE:
-        {
-            Sid = (PSID)&((PSYSTEM_ALARM_ACE)Ace)->SidStart;
+            Sid = (PSID)((ULONG_PTR)&((PKNOWN_OBJECT_ACE)Ace)->SidStart + GuidSize);
             break;
         }
 
diff --git a/sdk/include/xdk/setypes.h b/sdk/include/xdk/setypes.h
index a46e4295274..0a538747bda 100644
--- a/sdk/include/xdk/setypes.h
+++ b/sdk/include/xdk/setypes.h
@@ -801,6 +801,10 @@ typedef struct _SYSTEM_MANDATORY_LABEL_ACE {
   $ULONG SidStart;
 } SYSTEM_MANDATORY_LABEL_ACE, *PSYSTEM_MANDATORY_LABEL_ACE;
 
+/* Object ACE flags */
+#define ACE_OBJECT_TYPE_PRESENT           0x00000001
+#define ACE_INHERITED_OBJECT_TYPE_PRESENT 0x00000002
+
 #define SYSTEM_MANDATORY_LABEL_NO_WRITE_UP   0x1
 #define SYSTEM_MANDATORY_LABEL_NO_READ_UP    0x2
 #define SYSTEM_MANDATORY_LABEL_NO_EXECUTE_UP 0x4