diff --git a/R/theme.R b/R/theme.R
index 34b82d0f96..7f6c1b93fd 100644
--- a/R/theme.R
+++ b/R/theme.R
@@ -990,7 +990,7 @@ combine_elements <- function(e1, e2) {
 
   # If e2 is 'richer' than e1, fill e2 with e1 parameters
   is_subclass <- !any(inherits(e2, class(e1), which = TRUE) == 0)
-  is_subclass <- is_subclass && length(setdiff(class(e2), class(e1)) > 0)
+  is_subclass <- is_subclass && length(setdiff(class(e2), class(e1))) > 0
   if (is_subclass) {
     new <- defaults(e1, e2)
     e2[names(new)] <- new
diff --git a/tests/testthat/test-layer.R b/tests/testthat/test-layer.R
index 0c65c430df..23d7ef5ed6 100644
--- a/tests/testthat/test-layer.R
+++ b/tests/testthat/test-layer.R
@@ -148,10 +148,10 @@ test_that("layer warns for constant aesthetics", {
 test_that("layer names can be resolved", {
 
   p <- ggplot() + geom_point() + geom_point()
-  expect_equal(names(p$layers), c("geom_point", "geom_point...2"))
+  expect_named(p$layers, c("geom_point", "geom_point...2"))
 
   p <- ggplot() + geom_point(name = "foo") + geom_point(name = "bar")
-  expect_equal(names(p$layers), c("foo", "bar"))
+  expect_named(p$layers, c("foo", "bar"))
 
   l <- geom_point(name = "foobar")
   expect_snapshot(p + l + l, error = TRUE)