diff --git a/package.xml b/package.xml
index 341c78ba3e..9e402d2c4b 100644
--- a/package.xml
+++ b/package.xml
@@ -1,7 +1,8 @@
 <?xml version="1.0"?>
-<package format="2">
+<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
+<package format="3">
   <name>gtsam</name>
-  <version>4.1.0</version>
+  <version>4.2.0</version>
   <description>gtsam</description>
 
   <maintainer email="gtsam@lists.gatech.edu">Frank Dellaert</maintainer>