diff --git a/toolkit/components/pictureinpicture/tests/browser.ini b/toolkit/components/pictureinpicture/tests/browser.ini
index 1d77f944f300..eca98fb2c361 100644
--- a/toolkit/components/pictureinpicture/tests/browser.ini
+++ b/toolkit/components/pictureinpicture/tests/browser.ini
@@ -73,6 +73,9 @@ skip-if = os == "win" && bits == 64 && debug # Bug 1683002
[browser_stripVideoStyles.js]
[browser_tabIconOverlayPiP.js]
[browser_thirdPartyIframe.js]
+[browser_toggleButtonOnNanDuration.js]
+support-files =
+ test-page-with-nan-video-duration.html
[browser_toggleAfterTabTearOutIn.js]
skip-if = (os == 'linux' && bits == 64) || (os == 'mac' && !asan && !debug) # Bug 1605546
[browser_toggleButtonOverlay.js]
diff --git a/toolkit/components/pictureinpicture/tests/browser_toggleButtonOnNanDuration.js b/toolkit/components/pictureinpicture/tests/browser_toggleButtonOnNanDuration.js
new file mode 100644
index 000000000000..6eaa4b5bcd1c
--- /dev/null
+++ b/toolkit/components/pictureinpicture/tests/browser_toggleButtonOnNanDuration.js
@@ -0,0 +1,32 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * Tests that we do not show the Picture-in-Picture toggle on video
+ * elements that have a NaN duration.
+ */
+add_task(async function test_toggleButtonOnNanDuration() {
+ await BrowserTestUtils.withNewTab(
+ {
+ url: TEST_PAGE_WITH_NAN_VIDEO_DURATION,
+ gBrowser,
+ },
+ async browser => {
+ const VIDEO_ID = "test-video";
+
+ await SpecialPowers.spawn(browser, [VIDEO_ID], async videoID => {
+ let video = content.document.getElementById(videoID);
+ if (video.readyState < content.HTMLMediaElement.HAVE_ENOUGH_DATA) {
+ info(`Waiting for 'canplaythrough' for ${videoID}`);
+ await ContentTaskUtils.waitForEvent(video, "canplaythrough");
+ }
+ });
+
+ await testToggleHelper(browser, "nan-duration", false);
+
+ await testToggleHelper(browser, "test-video", true);
+ }
+ );
+});
diff --git a/toolkit/components/pictureinpicture/tests/test-page-with-nan-video-duration.html b/toolkit/components/pictureinpicture/tests/test-page-with-nan-video-duration.html
index aa87dac90159..b16c3682a01a 100644
--- a/toolkit/components/pictureinpicture/tests/test-page-with-nan-video-duration.html
+++ b/toolkit/components/pictureinpicture/tests/test-page-with-nan-video-duration.html
@@ -3,6 +3,7 @@
Bug 1679174
+
diff --git a/toolkit/content/widgets/videocontrols.js b/toolkit/content/widgets/videocontrols.js
index a3e6122d0896..78c37349f605 100644
--- a/toolkit/content/widgets/videocontrols.js
+++ b/toolkit/content/widgets/videocontrols.js
@@ -147,6 +147,10 @@ this.VideoControlsWidget = class {
someVideo,
reflowedDimensions
) {
+ if (isNaN(someVideo.duration)) {
+ return false;
+ }
+
if (
prefs["media.videocontrols.picture-in-picture.video-toggle.always-show"]
) {