diff --git a/src/main/java/com/jme3/bullet/collision/shapes/CustomConvexShape.java b/src/main/java/com/jme3/bullet/collision/shapes/CustomConvexShape.java
index c477c60a..2a66dfc9 100644
--- a/src/main/java/com/jme3/bullet/collision/shapes/CustomConvexShape.java
+++ b/src/main/java/com/jme3/bullet/collision/shapes/CustomConvexShape.java
@@ -143,6 +143,10 @@ protected CustomConvexShape(Vector3f halfExtents) {
      * @param iz the desired Z-axis rotational inertia for mass=1 (>0)
      */
     protected void setScaledInertia(float ix, float iy, float iz) {
+        Validate.positive(ix, "X-axis inertia");
+        Validate.positive(iy, "Y-axis inertia");
+        Validate.positive(iz, "Z-axis inertia");
+
         inertia.set(ix, iy, iz);
 
         long shapeId = nativeId();