diff --git a/indra/newview/llviewerobject.h b/indra/newview/llviewerobject.h
index 72505528f0e78f49ffdb18be946b8d1ddb88b413..a18d07d970aa95fc6358b036e72c9f8c21df99d8 100644
--- a/indra/newview/llviewerobject.h
+++ b/indra/newview/llviewerobject.h
@@ -28,6 +28,7 @@
 #define LL_LLVIEWEROBJECT_H
 
 #include <map>
+#include <unordered_map>
 
 #include "llassetstorage.h"
 //#include "llhudicon.h"