diff --git a/db/internal_stats.cc b/db/internal_stats.cc
index afe3f7141..87ed9c60f 100644
--- a/db/internal_stats.cc
+++ b/db/internal_stats.cc
@@ -1406,7 +1406,7 @@ void InternalStats::DumpCFFileHistogram(std::string* value) {
         << blob_file_read_latency_.ToString() << '\n';
   }
 
-  *value = oss.str();
+  value->append(oss.str());
 }
 
 #else