diff --git a/R/scale-.R b/R/scale-.R
index 66a0c91de4..aef461da93 100644
--- a/R/scale-.R
+++ b/R/scale-.R
@@ -1454,5 +1454,5 @@ trans_support_nbreaks <- function(trans) {
 }
 
 allow_lambda <- function(x) {
-  if (is_formula(x)) as_function(x) else x
+  if (is_formula(x, lhs = FALSE)) as_function(x) else x
 }
diff --git a/tests/testthat/test-utilities.R b/tests/testthat/test-utilities.R
index 107e22e063..4768bbf3da 100644
--- a/tests/testthat/test-utilities.R
+++ b/tests/testthat/test-utilities.R
@@ -188,6 +188,24 @@ test_that("expose/ignore_data() can round-trip a data.frame", {
 
 })
 
+test_that("allow_lambda converts the correct cases", {
+
+  f <- allow_lambda(function(x) x + 1)
+  expect_equal(f(1), 2)
+
+  f <- allow_lambda(~ .x + 1)
+  expect_equal(f(1), 2)
+
+  f <- allow_lambda("A")
+  expect_equal(f, "A")
+
+  f <- allow_lambda(expression(A))
+  expect_equal(f, expression(A))
+
+  f <- allow_lambda(bquote("foo"~"bar"))
+  expect_equal(f, call("~", "foo", "bar"))
+})
+
 test_that("summary method gives a nice summary", {
   # This test isn't important enough to break anything on CRAN
   skip_on_cran()