diff --git a/dlls/comctl32/listview.c b/dlls/comctl32/listview.c
index ab9493679bf..b84600a46ae 100644
--- a/dlls/comctl32/listview.c
+++ b/dlls/comctl32/listview.c
@@ -2352,7 +2352,7 @@ static void LISTVIEW_GetItemBox(const LISTVIEW_INFO *infoPtr, INT nItem, LPRECT
 }
 
 /* LISTVIEW_MapIdToIndex helper */
-INT CALLBACK MapIdSearchCompare(LPVOID p1, LPVOID p2, LPARAM lParam)
+static INT CALLBACK MapIdSearchCompare(LPVOID p1, LPVOID p2, LPARAM lParam)
 {
     ITEM_ID *id1 = (ITEM_ID*)p1;
     ITEM_ID *id2 = (ITEM_ID*)p2;