diff --git a/reactos/include/ndk/cmfuncs.h b/reactos/include/ndk/cmfuncs.h
index f8aac16d104..b9cd568d22a 100644
--- a/reactos/include/ndk/cmfuncs.h
+++ b/reactos/include/ndk/cmfuncs.h
@@ -234,7 +234,7 @@ NTSTATUS
 NTAPI
 NtQueryOpenSubKeys(
     IN POBJECT_ATTRIBUTES TargetKey,
-    IN ULONG HandleCount
+    OUT PULONG HandleCount
 );
 
 NTSTATUS
diff --git a/reactos/ntoskrnl/config/ntapi.c b/reactos/ntoskrnl/config/ntapi.c
index f177ececa49..62a2232d9a1 100644
--- a/reactos/ntoskrnl/config/ntapi.c
+++ b/reactos/ntoskrnl/config/ntapi.c
@@ -930,7 +930,7 @@ NtQueryMultipleValueKey(IN HANDLE KeyHandle,
 NTSTATUS
 NTAPI
 NtQueryOpenSubKeys(IN POBJECT_ATTRIBUTES TargetKey,
-                   IN ULONG HandleCount)
+                   OUT PULONG HandleCount)
 {
     UNIMPLEMENTED;
     return STATUS_NOT_IMPLEMENTED;