diff --git a/indra/llcommon/llsd.cpp b/indra/llcommon/llsd.cpp
index 862b6b5ebc27046eca696f825ad116d074c4e9ed..b0801745d7bb285c7e446006d30754fc48e1e6ae 100644
--- a/indra/llcommon/llsd.cpp
+++ b/indra/llcommon/llsd.cpp
@@ -964,7 +964,7 @@ std::string		LLSD::typeString(Type type)
 		"Array"
 	};
 
-	if (0 <= type < (sizeof(sTypeNameArray)/sizeof(sTypeNameArray[0])))
+	if (0 <= type && type < (sizeof(sTypeNameArray)/sizeof(sTypeNameArray[0])))
 	{
 		return sTypeNameArray[type];
 	}