diff --git a/druntime/src/core/sys/windows/commctrl.d b/druntime/src/core/sys/windows/commctrl.d
index dabee5672b..de81bbc2ad 100644
--- a/druntime/src/core/sys/windows/commctrl.d
+++ b/druntime/src/core/sys/windows/commctrl.d
@@ -5859,7 +5859,7 @@ BOOL TreeView_DeleteItem(HWND w, HTREEITEM i) {
     return cast(BOOL) SendMessage(w, TVM_DELETEITEM, 0, cast(LPARAM) i);
 }
 
-BOOL TreeView_DeleteAllItems(HWND w) {
+BOOL TreeView_DeleteAllItems(HWND w) @system {
     return cast(BOOL) SendMessage(w, TVM_DELETEITEM, 0, cast(LPARAM) TVI_ROOT);
 }