diff --git a/filesystem_verifier_action.h b/filesystem_verifier_action.h
index 9935dea..7a6930e 100644
--- a/filesystem_verifier_action.h
+++ b/filesystem_verifier_action.h
@@ -45,6 +45,9 @@
   kKernel,
 };
 
+// Return the partition name string for the passed partition type.
+std::string PartitionTypeToString(const PartitionType partition_type);
+
 class FilesystemVerifierAction : public InstallPlanAction {
  public:
   FilesystemVerifierAction(SystemState* system_state,