diff --git a/AsyncDisplayKit/ASCollectionView.mm b/AsyncDisplayKit/ASCollectionView.mm index 31191d42d3..08f4b43502 100644 --- a/AsyncDisplayKit/ASCollectionView.mm +++ b/AsyncDisplayKit/ASCollectionView.mm @@ -256,6 +256,7 @@ static BOOL _isInterceptedSelector(SEL sel) { if (_flowLayoutInspector == nil) { UICollectionViewFlowLayout *layout = (UICollectionViewFlowLayout *)self.collectionViewLayout; + ASDisplayNodeAssertNotNil(layout, @"Collection view layout must be a flow layout to use the built-in inspector"); _flowLayoutInspector = [[ASCollectionViewFlowLayoutInspector alloc] initWithCollectionView:self flowLayout:layout]; }