diff --git a/js/engine.js b/js/engine.js
index a96e953..0414ce6 100644
--- a/js/engine.js
+++ b/js/engine.js
@@ -77,13 +77,15 @@ function updateRates() {
         G.userRate += 5 * timmyCount * (timmyMult - 1);
     }
 
-    // Bilbo randomness: 10% chance of massive creative burst
-    if (G.buildings.bilbo > 0 && Math.random() < CONFIG.BILBO_BURST_CHANCE) {
-        G.creativityRate += 50 * G.buildings.bilbo;
-    }
-    // Bilbo vanishing: 5% chance of zero creativity this tick
-    if (G.buildings.bilbo > 0 && Math.random() < CONFIG.BILBO_VANISH_CHANCE) {
-        G.creativityRate = 0;
+    // Bilbo randomness: flags are set per-tick in tick(), not here
+    // updateRates() is called from many non-tick contexts (buy, resolve, sprint)
+    if (G.buildings.bilbo > 0) {
+        if (G.bilboBurstActive) {
+            G.creativityRate += 50 * G.buildings.bilbo;
+        }
+        if (G.bilboVanishActive) {
+            G.creativityRate = 0;
+        }
     }
 
     // Allegro requires trust