diff --git a/ports/libsimpleservo/api/src/lib.rs b/ports/libsimpleservo/api/src/lib.rs
index 952d85f9d31..0984b7c49f3 100644
--- a/ports/libsimpleservo/api/src/lib.rs
+++ b/ports/libsimpleservo/api/src/lib.rs
@@ -130,6 +130,8 @@ 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.
+    fn on_media_session(&self, active: bool);
 }
 
 pub struct ServoGlue {
diff --git a/ports/libsimpleservo/capi/src/lib.rs b/ports/libsimpleservo/capi/src/lib.rs
index c6b27ae6d48..4fbd239000e 100644
--- a/ports/libsimpleservo/capi/src/lib.rs
+++ b/ports/libsimpleservo/capi/src/lib.rs
@@ -216,6 +216,7 @@ pub struct CHostCallbacks {
     pub on_ime_state_changed: extern "C" fn(show: bool),
     pub get_clipboard_contents: extern "C" fn() -> *const c_char,
     pub set_clipboard_contents: extern "C" fn(contents: *const c_char),
+    pub on_media_session: extern "C" fn(active: bool),
 }
 
 /// Servo options
@@ -708,4 +709,9 @@ impl HostTrait for HostCallbacks {
         let contents = CString::new(contents).expect("Can't create string");
         (self.0.set_clipboard_contents)(contents.as_ptr());
     }
+
+    fn on_media_session(&self, active: bool) {
+        debug!("on_media_session (active: {:?})", active);
+        (self.0.on_media_session)(active);
+    }
 }