diff --git a/tbc/sim.go b/tbc/sim.go
index c7bf13c..992da73 100644
--- a/tbc/sim.go
+++ b/tbc/sim.go
@@ -132,7 +132,7 @@ func (sim *Simulation) reset() {
 	sim.CDs = [MagicIDLen]time.Duration{}
 	sim.auras = [MagicIDLen]Aura{}
 	if len(sim.activeAuraIDs) > 0 {
-		sim.activeAuraIDs = sim.activeAuraIDs[len(sim.activeAuraIDs)-1:] // chop off end of activeids slice, faster than making a new one
+		sim.activeAuraIDs = sim.activeAuraIDs[:0] // chop off end of activeids slice, faster than making a new one
 	}
 	sim.metrics = SimMetrics{
 		Casts: make([]*Cast, 0, 1000),
diff --git a/ui/lib.wasm b/ui/lib.wasm
index 2c215f9..10e4d0d 100755
Binary files a/ui/lib.wasm and b/ui/lib.wasm differ