diff --git a/src/FieldNames.cpp b/src/FieldNames.cpp
index be5fe00201..122550eb18 100644
--- a/src/FieldNames.cpp
+++ b/src/FieldNames.cpp
@@ -34,8 +34,6 @@ SField::ref SField::getField(int code)
 	if ((type <= 0) || (field <= 0))
 		return sfInvalid;
 
-	boost::mutex::scoped_lock sl(mapMutex);
-
 	boost::recursive_mutex::scoped_lock sl(mapMutex);
 
 	std::map<int, SField::ptr>::iterator it = codeToField.find(code);