diff --git a/src/clients/supervisor_client.rs b/src/clients/supervisor_client.rs
index 6da18b2..7d48561 100644
--- a/src/clients/supervisor_client.rs
+++ b/src/clients/supervisor_client.rs
@@ -104,6 +104,10 @@ impl SupervisorClient {
         Ok(BASE64_STANDARD.encode(s.as_bytes()))
     }
 
+    fn encode_topic(topic: &[u8]) -> String {
+        BASE64_STANDARD.encode(topic)
+    }
+
     fn extract_message_id_from_result(result: &Value) -> Option<String> {
         // Two possibilities per Mycelium spec oneOf:
         // - PushMessageResponseId: { "id": "0123456789abcdef" }
@@ -120,7 +124,12 @@ impl SupervisorClient {
         let payload_b64 = Self::encode_payload(&inner)?;
         let result = self
             .mycelium
-            .push_message(&self.destination, &self.topic, &payload_b64, None)
+            .push_message(
+                &self.destination,
+                &Self::encode_topic(self.topic.as_bytes()),
+                &payload_b64,
+                None,
+            )
             .await?;
 
         if let Some(id) = MyceliumClient::extract_message_id_from_result(&result) {