diff --git a/reactos/ntoskrnl/mm/virtual.c b/reactos/ntoskrnl/mm/virtual.c
index 98f1f15306d..9aa23fbc5e9 100644
--- a/reactos/ntoskrnl/mm/virtual.c
+++ b/reactos/ntoskrnl/mm/virtual.c
@@ -555,6 +555,7 @@ MiQueryVirtualMemory(IN HANDLE ProcessHandle,
 
         default:
         {
+            DPRINT1("Unsupported or unimplemented class: %lx\n", VirtualMemoryInformationClass);
             Status = STATUS_INVALID_INFO_CLASS;
             *ResultLength = 0;
             break;