diff --git a/components/embedder_traits/lib.rs b/components/embedder_traits/lib.rs
index 949b3ba5acb..da526d5f478 100644
--- a/components/embedder_traits/lib.rs
+++ b/components/embedder_traits/lib.rs
@@ -162,6 +162,9 @@ pub enum EmbedderMsg {
     Shutdown,
     /// Report a complete sampled profile
     ReportProfile(Vec<u8>),
+    /// Sent when a media session is activated or deactivated.
+    /// There can only be a single active media session.
+    MediaSession(bool),
 }
 
 impl Debug for EmbedderMsg {
@@ -194,6 +197,7 @@ impl Debug for EmbedderMsg {
             EmbedderMsg::AllowOpeningBrowser(..) => write!(f, "AllowOpeningBrowser"),
             EmbedderMsg::BrowserCreated(..) => write!(f, "BrowserCreated"),
             EmbedderMsg::ReportProfile(..) => write!(f, "ReportProfile"),
+            EmbedderMsg::MediaSession(..) => write!(f, "MediaSession"),
         }
     }
 }
diff --git a/ports/libsimpleservo/api/src/lib.rs b/ports/libsimpleservo/api/src/lib.rs
index 0984b7c49f3..4f1d0aa6a22 100644
--- a/ports/libsimpleservo/api/src/lib.rs
+++ b/ports/libsimpleservo/api/src/lib.rs
@@ -130,7 +130,7 @@ pub trait HostTrait {
     fn get_clipboard_contents(&self) -> Option<String>;
     /// Sets system clipboard contents
     fn set_clipboard_contents(&self, contents: String);
-    /// Called when a media session is activated or deactived.
+    /// Called when a media session is activated or deactivated.
     fn on_media_session(&self, active: bool);
 }
 
@@ -583,6 +583,9 @@ impl ServoGlue {
                 EmbedderMsg::HideIME => {
                     self.callbacks.host_callbacks.on_ime_state_changed(false);
                 },
+                EmbedderMsg::MediaSession(active) => {
+                    self.callbacks.host_callbacks.on_media_session(active);
+                },
                 EmbedderMsg::Status(..) |
                 EmbedderMsg::SelectFiles(..) |
                 EmbedderMsg::MoveTo(..) |