diff --git a/runelite-client/src/main/java/net/runelite/client/ui/overlay/infobox/Timer.java b/runelite-client/src/main/java/net/runelite/client/ui/overlay/infobox/Timer.java
index c9a3664222..4f3c7be775 100644
--- a/runelite-client/src/main/java/net/runelite/client/ui/overlay/infobox/Timer.java
+++ b/runelite-client/src/main/java/net/runelite/client/ui/overlay/infobox/Timer.java
@@ -96,6 +96,7 @@ public class Timer extends InfoBox
 
 	public void setDuration(Duration duration)
 	{
+		Preconditions.checkArgument(!duration.isNegative(), "negative duration");
 		this.duration = duration;
 		endTime = startTime.plus(duration);
 	}