diff --git a/Cargo.lock b/Cargo.lock
index 06d6d7667..c4394f2ef 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3006,6 +3006,7 @@ dependencies = [
  "anyhow",
  "chrono",
  "gio",
+ "gst-plugin-fmp4",
  "gst-plugin-version-helper",
  "gstreamer",
  "gstreamer-app",
diff --git a/net/hlssink3/Cargo.toml b/net/hlssink3/Cargo.toml
index ee9479dba..fa7a4af91 100644
--- a/net/hlssink3/Cargo.toml
+++ b/net/hlssink3/Cargo.toml
@@ -23,6 +23,7 @@ gst-check.workspace = true
 gst-pbutils = { workspace = true, features = ["v1_20"] }
 m3u8-rs = "6.0"
 anyhow = "1"
+gst-plugin-fmp4 = { path = "../../mux/fmp4" }
 
 [build-dependencies]
 gst-plugin-version-helper.workspace = true
diff --git a/net/hlssink3/tests/hlscmafsink.rs b/net/hlssink3/tests/hlscmafsink.rs
index 1880bd3fa..33ea6adbb 100644
--- a/net/hlssink3/tests/hlscmafsink.rs
+++ b/net/hlssink3/tests/hlscmafsink.rs
@@ -21,6 +21,7 @@ fn init() {
 
     INIT.call_once(|| {
         gst::init().unwrap();
+        gstfmp4::plugin_register_static().expect("Need cmafmux for hlscmafsink test");
         gsthlssink3::plugin_register_static().expect("hlscmafsink test");
     });
 }