diff --git a/tests/testthat/test-ecxsys.R b/tests/testthat/test-ecxsys.R
index c668001aab6ed1427de72f3f65a69f5986f61352..ffc26085afb21fb1ab0a43012670ba63c3edb999 100644
--- a/tests/testthat/test-ecxsys.R
+++ b/tests/testthat/test-ecxsys.R
@@ -171,7 +171,7 @@ test_that("the curves have not changed", {
 test_that("the returned fn works the same way as internally", {
     # I don't know why it would fail but it doesn't hurt to test it.
     curves <- mod$curves
-    curves$concentration_for_plots <- NULL  # remove column "use_for_plotting"
+    curves$concentration_for_plots <- NULL
     expect_identical(curves, predict_ecxsys(mod, curves$concentration))
 })