diff --git a/lib/redis/rediswriter-objects.cpp b/lib/redis/rediswriter-objects.cpp
index 9a54cdaae..f2ddba57a 100644
--- a/lib/redis/rediswriter-objects.cpp
+++ b/lib/redis/rediswriter-objects.cpp
@@ -662,7 +662,7 @@ Dictionary::Ptr RedisWriter::SerializeState(const Checkable::Ptr& checkable)
 	if (cr) {
 		attrs->Set("output", CompatUtility::GetCheckResultOutput(cr));
 		attrs->Set("long_output", CompatUtility::GetCheckResultLongOutput(cr));
-		attrs->Set("performance_data", cr->GetPerformanceData());
+		attrs->Set("performance_data", JsonEncode(cr->GetPerformanceData()));
 		attrs->Set("command", cr->GetCommand());
 		attrs->Set("execution_time", cr->CalculateExecutionTime());
 		attrs->Set("latency", cr->CalculateLatency());