diff --git a/proto/classpaths.proto b/proto/classpaths.proto
index 829c14c..97f288e 100644
--- a/proto/classpaths.proto
+++ b/proto/classpaths.proto
@@ -21,6 +21,7 @@ enum Classpath {
   BOOTCLASSPATH = 1;
   SYSTEMSERVERCLASSPATH = 2;
   DEX2OATBOOTCLASSPATH = 3;
+  STANDALONE_SYSTEMSERVER_JARS = 4;
 }
 
 // Individual entry in a classpath variable.