diff --git a/reactos/dll/win32/advapi32/reg/reg.c b/reactos/dll/win32/advapi32/reg/reg.c
index a6aa22ecae5..c02d180d520 100644
--- a/reactos/dll/win32/advapi32/reg/reg.c
+++ b/reactos/dll/win32/advapi32/reg/reg.c
@@ -3604,6 +3604,11 @@ RegQueryInfoKeyA(HKEY hKey,
     NTSTATUS Status;
     DWORD cClass = 0;
 
+    if ((lpClass) && (!lpcClass))
+    {
+        return ERROR_INVALID_PARAMETER;
+    }
+
     RtlInitUnicodeString(&UnicodeString,
                          NULL);
     if (lpClass != NULL)