diff --git a/Libraries/LibWeb/MediaSourceExtensions/ManagedMediaSource.idl b/Libraries/LibWeb/MediaSourceExtensions/ManagedMediaSource.idl
index 0ca55b7c29..5da004dfee 100644
--- a/Libraries/LibWeb/MediaSourceExtensions/ManagedMediaSource.idl
+++ b/Libraries/LibWeb/MediaSourceExtensions/ManagedMediaSource.idl
@@ -2,7 +2,7 @@
 #import <MediaSourceExtensions/MediaSource.idl>
 
 // https://w3c.github.io/media-source/#managedmediasource-interface
-[Exposed=(Window,DedicatedWorker)]
+[Exposed=(Window,DedicatedWorker), Experimental]
 interface ManagedMediaSource : MediaSource {
     constructor();
     [FIXME] readonly attribute boolean streaming;
diff --git a/Libraries/LibWeb/MediaSourceExtensions/MediaSource.idl b/Libraries/LibWeb/MediaSourceExtensions/MediaSource.idl
index 18e09318bb..726e49f578 100644
--- a/Libraries/LibWeb/MediaSourceExtensions/MediaSource.idl
+++ b/Libraries/LibWeb/MediaSourceExtensions/MediaSource.idl
@@ -16,7 +16,7 @@ enum EndOfStreamError {
 };
 
 // https://w3c.github.io/media-source/#dom-mediasource
-[Exposed=(Window,DedicatedWorker)]
+[Exposed=(Window,DedicatedWorker), Experimental]
 interface MediaSource : EventTarget {
     constructor();
 
diff --git a/Libraries/LibWeb/MediaSourceExtensions/MediaSourceHandle.idl b/Libraries/LibWeb/MediaSourceExtensions/MediaSourceHandle.idl
index fbc2a92cc9..169cb412d2 100644
--- a/Libraries/LibWeb/MediaSourceExtensions/MediaSourceHandle.idl
+++ b/Libraries/LibWeb/MediaSourceExtensions/MediaSourceHandle.idl
@@ -1,3 +1,3 @@
 // https://w3c.github.io/media-source/#dom-mediasourcehandle
-[Transferable, Exposed=(Window,DedicatedWorker)]
+[Transferable, Exposed=(Window,DedicatedWorker), Experimental]
 interface MediaSourceHandle {};