diff --git a/test/broadcast.jl b/test/broadcast.jl
index 808e22d..26d07cd 100644
--- a/test/broadcast.jl
+++ b/test/broadcast.jl
@@ -15,6 +15,11 @@
     for l in p1.levels
         @test sum(l) == prod(size(l))
     end
+
+    @test_throws ArgumentError pyramid .- pyramid.base
+    @test_throws ArgumentError pyramid .- pyramid.base.data
+    pyr_small = Pyramid(dd, tilesize=200)
+    @test_throws ErrorException pyr_small .- pyramid
     #tname = tempname() * ".tif"
     #r = Raster(dd)
     #write(tname, r, driver="cog", force=true)