diff --git a/src/ca-state.cpp b/src/ca-state.cpp
index 3b05e03..185fbdd 100644
--- a/src/ca-state.cpp
+++ b/src/ca-state.cpp
@@ -103,7 +103,9 @@
     os << "Challenge remaining tries:" << request.m_challengeState->m_remainingTries << " times\n";
     os << "Challenge remaining time: " << request.m_challengeState->m_remainingTime.count() << " seconds\n";
     os << "Challenge last update: " << time::toIsoString(request.m_challengeState->m_timestamp) << "\n";
-    os << "Challenge secret:\n" << convertJson2String(request.m_challengeState->m_secrets) << "\n";
+    std::stringstream ss;
+    boost::property_tree::write_json(ss, request.m_challengeState->m_secrets);
+    os << "Challenge secret:\n" << ss.str() << "\n";
   }
   os << "Certificate:\n";
   util::IndentedStream os2(os, "  ");