diff --git a/core/src/main/java/info/openrocket/core/file/openrocket/savers/RocketComponentSaver.java b/core/src/main/java/info/openrocket/core/file/openrocket/savers/RocketComponentSaver.java
index f56690a0c..a277358f1 100644
--- a/core/src/main/java/info/openrocket/core/file/openrocket/savers/RocketComponentSaver.java
+++ b/core/src/main/java/info/openrocket/core/file/openrocket/savers/RocketComponentSaver.java
@@ -200,7 +200,8 @@ public class RocketComponentSaver {
 		
 		String baseName = trans.getBaseText("material", mat.getName());
 		
-		return str + " density=\"" + mat.getDensity() + "\">" + TextUtil.escapeXML(baseName) + "</" + tag + ">";
+		return str + " density=\"" + mat.getDensity() + "\" group=\"" + mat.getGroup().getDatabaseString() + "\">" +
+				TextUtil.escapeXML(baseName) + "</" + tag + ">";
 	}