diff --git a/core/src/net/sf/openrocket/file/openrocket/importt/DocumentConfig.java b/core/src/net/sf/openrocket/file/openrocket/importt/DocumentConfig.java
index 138456aa8..16f733ec9 100644
--- a/core/src/net/sf/openrocket/file/openrocket/importt/DocumentConfig.java
+++ b/core/src/net/sf/openrocket/file/openrocket/importt/DocumentConfig.java
@@ -369,7 +369,9 @@ class DocumentConfig {
 		setters.put("MassObject:packedlength", new DoubleSetter(
 				Reflection.findMethod(MassObject.class, "setLength", double.class)));
 		setters.put("MassObject:packedradius", new DoubleSetter(
-				Reflection.findMethod(MassObject.class, "setRadius", double.class)));
+				Reflection.findMethod(MassObject.class, "setRadius", double.class),
+				"auto", " ",
+				Reflection.findMethod(MassObject.class, "setRadiusAutomatic", boolean.class)));
 		setters.put("MassObject:radialposition", new DoubleSetter(
 				Reflection.findMethod(MassObject.class, "setRadialPosition", double.class)));
 		setters.put("MassObject:radialdirection", new DoubleSetter(
diff --git a/core/src/net/sf/openrocket/file/openrocket/savers/MassObjectSaver.java b/core/src/net/sf/openrocket/file/openrocket/savers/MassObjectSaver.java
index 298cb2636..3cbf57605 100644
--- a/core/src/net/sf/openrocket/file/openrocket/savers/MassObjectSaver.java
+++ b/core/src/net/sf/openrocket/file/openrocket/savers/MassObjectSaver.java
@@ -14,7 +14,11 @@ public class MassObjectSaver extends InternalComponentSaver {
 		MassObject mass = (MassObject) c;
 
 		elements.add("<packedlength>" + mass.getLength() + "</packedlength>");
-		elements.add("<packedradius>" + mass.getRadius() + "</packedradius>");
+		if (mass.isRadiusAutomatic()) {
+			elements.add("<packedradius>auto " + mass.getRadius() + "</packedradius>");
+		} else {
+			elements.add("<packedradius>" + mass.getRadius() + "</packedradius>");
+		}
 		elements.add("<radialposition>" + mass.getRadialPosition() + "</radialposition>");
 		elements.add("<radialdirection>" + (mass.getRadialDirection() * 180.0 / Math.PI)
 				+ "</radialdirection>");