diff --git a/test/test_tree_1d_eulermulti.jl b/test/test_tree_1d_eulermulti.jl
index b6e15ee02e6..0e3dfa7e4a0 100644
--- a/test/test_tree_1d_eulermulti.jl
+++ b/test/test_tree_1d_eulermulti.jl
@@ -20,6 +20,7 @@ EXAMPLES_DIR = pkgdir(Trixi, "examples", "tree_1d_dgsem")
     u = [-1.4632513788889214, 0.9908786980927811, 0.2909066990257628, 0.6256623915420473, 0.4905882754313441, 0.14481800501749112, 1.0333532872771651, 0.6805599818745411]
     w = cons2entropy(u, equations)
     @test w ≈ ForwardDiff.gradient(u -> Trixi.total_entropy(u, equations), u)
+    # test that `entropy2cons` is the inverse of `cons2entropy`
     @test entropy2cons(w, equations) ≈ u
 end