diff --git a/src/activitypub.rs b/src/activitypub.rs
index 2031fa5..8534fd1 100644
--- a/src/activitypub.rs
+++ b/src/activitypub.rs
@@ -34,7 +34,7 @@ pub struct Action<O> {
     pub action_type: String,
     pub id: String,
     pub actor: String,
-    pub to: Option<String>,
+    pub to: Option<serde_json::Value>,
     pub object: Option<O>,
 }
 
diff --git a/src/main.rs b/src/main.rs
index 0ab9d1b..43e035e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -167,7 +167,7 @@ async fn post_relay(
                 jsonld_context: serde_json::Value::String("https://www.w3.org/ns/activitystreams".to_string()),
                 action_type: "Accept".to_string(),
                 actor: target.uri(),
-                to: Some(endpoint.actor.id.clone()),
+                to: Some(json!(endpoint.actor.id.clone())),
                 id: action.id,
                 object: Some(endpoint.payload),
             };