Sqlite error: illegal first argument to matchinfo

I've been struggling with this for quite some time and have to throw in the towel. Using SQLite with Tcl:

set _query [sq_handle eval {SELECT matchinfo(column7) FROM myftstable WHERE column7 MATCH 'raindrops keep falling in my hat';}]
puts $_query

I keep getting this: error: illegal first argument to matchinfo

I only have the problem with matchinfo, which I need. Ordinary SELECT queries work fine.

I googled, but couldn't find anything useful.