diff --git a/NEWS.md b/NEWS.md
index 87ee727e..261c5ac4 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,9 @@
 # httr (development version)
 
+* An internal helper that checks for an interactive session in the OOB flow now
+  honors the `"rlang_interactive"` global option, in case it's necessary to
+  declare the session to be interactive (enough) for OOB (@jennybc, #734).
+
 # httr 1.4.4
 
 * Fix intermittent failing test.
diff --git a/R/oauth-init.R b/R/oauth-init.R
index c44477d7..0cdf0762 100644
--- a/R/oauth-init.R
+++ b/R/oauth-init.R
@@ -211,8 +211,12 @@ check_scope <- function(x) {
   paste(x, collapse = " ")
 }
 
-# Wrap base::interactive in a non-primitive function so that the call can be mocked for testing
-is_interactive <- function() interactive()
+# gargle needs to access (pseudo-)OOB flow from Google Colab, so we need to
+# be able to use the "rlang_interactive" option to signal that we are in
+# an environment that is interactive (enough) to complete this flow.
+is_interactive <- function() {
+  getOption("rlang_interactive") %||% interactive()
+}
 
 check_oob <- function(use_oob, oob_value = NULL) {
   if (!is.logical(use_oob) || length(use_oob) != 1) {
diff --git a/tests/testthat/test-oauth.R b/tests/testthat/test-oauth.R
index 563c51f2..fdd24643 100644
--- a/tests/testthat/test-oauth.R
+++ b/tests/testthat/test-oauth.R
@@ -111,13 +111,19 @@ test_that("oob must be a flag", {
 })
 
 test_that("can not use oob in non-interactive session", {
+  old <- options()
+  on.exit(options(old))
+  options(rlang_interactive = FALSE)
+
   expect_error(check_oob(TRUE), "interactive")
 })
 
 test_that("can not use custom oob value without enabling oob", {
   testthat::skip_if_not_installed("httpuv")
-  with_mock(
-    `httr:::is_interactive` = function() TRUE,
-    expect_error(check_oob(FALSE, "custom_value"), "custom oob value")
-  )
+
+  old <- options()
+  on.exit(options(old))
+  options(rlang_interactive = TRUE)
+
+  expect_error(check_oob(FALSE, "custom_value"), "custom oob value")
 })