diff --git a/dlls/quartz/filtermapper.c b/dlls/quartz/filtermapper.c
index db162c01339..2068131b9eb 100644
--- a/dlls/quartz/filtermapper.c
+++ b/dlls/quartz/filtermapper.c
@@ -1087,7 +1087,7 @@ static HRESULT WINAPI FilterMapper_EnumMatchingFilters(
 
     if (SUCCEEDED(hr))
     {
-        hr = IEnumRegFiltersImpl_Construct(regfilters, nb_mon, ppEnum);
+        hr = IEnumRegFiltersImpl_Construct(regfilters, idx, ppEnum);
     }
 
     for (idx = 0; idx < nb_mon; idx++)