diff --git a/src/test/unit.js b/src/test/unit.js
index 0680fbb11..81da21ac8 100644
--- a/src/test/unit.js
+++ b/src/test/unit.js
@@ -1,4 +1,5 @@
 import "test/unit/attachment_test"
+import "test/unit/bidi_test"
 import "test/unit/block_test"
 import "test/unit/composition_test"
 import "test/unit/document_test"
diff --git a/src/test/unit/bidi_test.js b/src/test/unit/bidi_test.js
new file mode 100644
index 000000000..17d104b97
--- /dev/null
+++ b/src/test/unit/bidi_test.js
@@ -0,0 +1,9 @@
+import { assert, test, testGroup } from "test/test_helper"
+import { getDirection } from "trix/core/helpers"
+
+testGroup("BIDI", () => {
+  test("detects text direction", () => {
+    assert.equal(getDirection("abc"), "ltr")
+    assert.equal(getDirection("אבג"), "rtl")
+  })
+})
diff --git a/src/trix/core/helpers/bidi.js b/src/trix/core/helpers/bidi.js
index 20efd506d..81fe0e380 100644
--- a/src/trix/core/helpers/bidi.js
+++ b/src/trix/core/helpers/bidi.js
@@ -6,12 +6,14 @@ const RTL_PATTERN =
 
 export const getDirection = (function() {
   const input = makeElement("input", { dir: "auto", name: "x", dirName: "x.dir" })
+  const textArea = makeElement("textarea", { dir: "auto", name: "y", dirName: "y.dir" })
   const form = makeElement("form")
   form.appendChild(input)
+  form.appendChild(textArea)
 
   const supportsDirName = (function() {
     try {
-      return new FormData(form).has(input.dirName)
+      return new FormData(form).has(textArea.dirName)
     } catch (error) {
       return false
     }
@@ -27,8 +29,8 @@ export const getDirection = (function() {
 
   if (supportsDirName) {
     return function(string) {
-      input.value = string
-      return new FormData(form).get(input.dirName)
+      textArea.value = string
+      return new FormData(form).get(textArea.dirName)
     }
   } else if (supportsDirSelector) {
     return function(string) {