diff --git a/core/src/net/sf/openrocket/rocketcomponent/RocketComponent.java b/core/src/net/sf/openrocket/rocketcomponent/RocketComponent.java
index 8329569c3..f6ef7fa22 100644
--- a/core/src/net/sf/openrocket/rocketcomponent/RocketComponent.java
+++ b/core/src/net/sf/openrocket/rocketcomponent/RocketComponent.java
@@ -1930,7 +1930,7 @@ public abstract class RocketComponent implements ChangeSource, Cloneable, Iterab
 	
 	protected static final double ringMass(double outerRadius, double innerRadius,
 			double length, double density) {
-		return Math.PI * (MathUtil.pow2(outerRadius) - MathUtil.pow2(innerRadius)) *
+		return Math.PI * Math.max(MathUtil.pow2(outerRadius) - MathUtil.pow2(innerRadius),0) *
 				length * density;
 	}