--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -1736,17 +1736,17 @@ pref("media.autoplay.default", 1); // 0=
   // Block WebAudio from playing automatically.
   pref("media.autoplay.block-webaudio", true);
 #else
   pref("media.autoplay.block-webaudio", false);
 #endif
 
 pref("media.videocontrols.picture-in-picture.enabled", true);
 pref("media.videocontrols.picture-in-picture.video-toggle.enabled", true);
-pref("media.videocontrols.picture-in-picture.video-toggle.visibility-threshold", "0.9");
+pref("media.videocontrols.picture-in-picture.video-toggle.visibility-threshold", "1.0");
 pref("media.videocontrols.picture-in-picture.keyboard-controls.enabled", true);
 
 #ifdef NIGHTLY_BUILD
   // Show the audio toggle for Picture-in-Picture.
   pref("media.videocontrols.picture-in-picture.audio-toggle.enabled", true);
   // Enable keyboard controls for Picture-in-Picture.
 #else
   pref("media.videocontrols.picture-in-picture.audio-toggle.enabled", false);

--- a/toolkit/actors/PictureInPictureChild.jsm
+++ b/toolkit/actors/PictureInPictureChild.jsm
@@ -257,17 +257,17 @@ class PictureInPictureToggleChild extend
     if (this.isDestroyed || !this.document) {
       return false;
     }
 
     let state = this.weakDocStates.get(this.document);
 
     let visibilityThresholdPref = Services.prefs.getFloatPref(
       TOGGLE_VISIBILITY_THRESHOLD_PREF,
-      "0.9"
+      "1.0"
     );
 
     if (!state) {
       state = {
         // A reference to the IntersectionObserver that's monitoring for videos
         // to become visible.
         intersectionObserver: null,
         // A WeakSet of videos that are supposedly visible, according to the
@@ -911,17 +911,17 @@ class PictureInPictureToggleChild extend
       // We cache the matchers process-wide. We'll skip this while running tests to make that
       // easier.
       let siteOverrides = this.toggleTesting
         ? PictureInPictureToggleChild.getSiteOverrides()
         : gSiteOverrides;
 
       let visibilityThresholdPref = Services.prefs.getFloatPref(
         TOGGLE_VISIBILITY_THRESHOLD_PREF,
-        "0.9"
+        "1.0"
       );
 
       // Do we have any toggle overrides? If so, try to apply them.
       for (let [override, { policy, visibilityThreshold }] of siteOverrides) {
         if (
           (policy || visibilityThreshold) &&
           override.matches(this.document.documentURI)
         ) {