Synonyms that reference local database show as "Invalid object name 'mysynonym'" in IntelliSense with SSMS 18.9.1, at least they do for me. I have found mentions of this "bug" going back to at least 2011. There is still no fix for this or workaround, other than defeating IntelliSense ? The use of synonyms isn't exactly rare. Having the query window full of red squiggles more or less defeats the utility of IntelliSense . I've tried opening, closing, clearing the IntelliSense cache, nothing works. It's like this on all of the SSMS instances I have access to.