diff --git a/gtk/gtkgrid.c b/gtk/gtkgrid.c
index 204c9ae44d..d735e63224 100644
--- a/gtk/gtkgrid.c
+++ b/gtk/gtkgrid.c
@@ -397,6 +397,8 @@ gtk_grid_init (GtkGrid *grid)
 
   priv->linedata[0].homogeneous = FALSE;
   priv->linedata[1].homogeneous = FALSE;
+
+  _gtk_orientable_set_style_classes (GTK_ORIENTABLE (grid));
 }
 
 static void