diff --git a/src/player.js b/src/player.js
index b8c5ec6..74f5e0d 100644
--- a/src/player.js
+++ b/src/player.js
@@ -618,8 +618,21 @@ export async function toggleRadioMode() {
 export async function fillRadioQueue() {
   if(!S.radioMode) return;
   try {
-    const r = await api('getRandomSongs', '&size=20');
-    const newSongs = r.randomSongs?.song || [];
+    const seed = S.queue[S.qIdx];
+    let newSongs = [];
+    if (seed?.id) {
+      const r = await api('getSimilarSongs2', `&id=${seed.id}&count=20`);
+      newSongs = r.similarSongs2?.song || [];
+    }
+    // Fall back to random if similar songs unavailable (no Last.fm config, unknown track, etc.)
+    if (!newSongs.length) {
+      const r = await api('getRandomSongs', '&size=20');
+      newSongs = r.randomSongs?.song || [];
+    }
+    // Deduplicate against songs already queued
+    const existingIds = new Set(S.queue.map(s => s.id));
+    newSongs = newSongs.filter(s => !existingIds.has(s.id));
+    if (!newSongs.length) return;
     const prevLen = S.queue.length;
     S.queue.push(...newSongs);
     renderQueue();