diff --git a/src/osx/cocoa/dataview.mm b/src/osx/cocoa/dataview.mm
index a2b20c00a0..a7ec7df23f 100644
--- a/src/osx/cocoa/dataview.mm
+++ b/src/osx/cocoa/dataview.mm
@@ -677,7 +677,6 @@ outlineView:(NSOutlineView*)outlineView
 -(NSDragOperation) outlineView:(NSOutlineView*)outlineView validateDrop:(id<NSDraggingInfo>)info proposedItem:(id)item proposedChildIndex:(NSInteger)index
 {
     wxUnusedVar(outlineView);
-    wxUnusedVar(index);
 
     return [self setupAndCallDataViewEvents:wxEVT_DATAVIEW_ITEM_DROP_POSSIBLE dropInfo:info item:item proposedChildIndex:index];
 }