diff --git a/dlls/ntdll/ntdll.spec b/dlls/ntdll/ntdll.spec
index b0cb43a8e92..60f70b119a2 100644
--- a/dlls/ntdll/ntdll.spec
+++ b/dlls/ntdll/ntdll.spec
@@ -463,7 +463,7 @@
 # @ stub RtlConvertPropertyToVariant
 @ stub RtlConvertSharedToExclusive
 @ stdcall RtlConvertSidToUnicodeString(ptr ptr long)
-# @ stub RtlConvertToAutoInheritSecurityObject
+@ stdcall RtlConvertToAutoInheritSecurityObject(ptr ptr ptr ptr long ptr)
 @ stub RtlConvertUiListToApiList
 @ stdcall -arch=win32 -ret64 RtlConvertUlongToLargeInteger(long)
 # @ stub RtlConvertVariantToProperty
diff --git a/dlls/ntdll/sec.c b/dlls/ntdll/sec.c
index 5e27730983f..b9eeccda616 100644
--- a/dlls/ntdll/sec.c
+++ b/dlls/ntdll/sec.c
@@ -1807,3 +1807,16 @@ NTSTATUS WINAPI RtlQueryInformationAcl(
 
     return status;
 }
+
+BOOL WINAPI RtlConvertToAutoInheritSecurityObject(
+        PSECURITY_DESCRIPTOR pdesc,
+        PSECURITY_DESCRIPTOR cdesc,
+        PSECURITY_DESCRIPTOR* ndesc,
+        GUID* objtype,
+        BOOL isdir,
+        PGENERIC_MAPPING genmap )
+{
+    FIXME("%p %p %p %p %d %p - stub\n", pdesc, cdesc, ndesc, objtype, isdir, genmap);
+
+    return FALSE;
+}