diff --git a/install_plan.cc b/install_plan.cc
index c378860..382eb4e 100644
--- a/install_plan.cc
+++ b/install_plan.cc
@@ -24,8 +24,8 @@
 
 namespace chromeos_update_engine {
 
-const char* kLegacyPartitionNameKernel = "KERNEL";
-const char* kLegacyPartitionNameRoot = "ROOT";
+const char* kLegacyPartitionNameKernel = "boot";
+const char* kLegacyPartitionNameRoot = "system";
 
 InstallPlan::InstallPlan(bool is_resume,
                          bool is_full_update,
diff --git a/install_plan.h b/install_plan.h
index 6e6f7ae..5e50626 100644
--- a/install_plan.h
+++ b/install_plan.h
@@ -31,6 +31,9 @@
 // parts of the update system about the install that should happen.
 namespace chromeos_update_engine {
 
+// The kernel and rootfs partition names used by the BootControlInterface when
+// handling update payloads with a major version 1. The names of the updated
+// partitions are include in the payload itself for major version 2.
 // TODO(deymo): Remove these constants from this interface once the InstallPlan
 // doesn't list the partitions explicitly.
 extern const char* kLegacyPartitionNameKernel;