diff --git a/css/css-grid/masonry/tentative/masonry-columns-item-containing-block-is-grid-content-width-ref.html b/css/css-grid/masonry/tentative/masonry-columns-item-containing-block-is-grid-content-width-ref.html
new file mode 100644
index 00000000000000..82fcaa3b2aa4a2
--- /dev/null
+++ b/css/css-grid/masonry/tentative/masonry-columns-item-containing-block-is-grid-content-width-ref.html
@@ -0,0 +1,4 @@
+
+
+Test passes if there is a filled green square.
+