Alternatives to connecting a ball and chain cord?

I was trying to child-proof some Ikea roller blinds. The blinds were controlled by a closed ball and chain loop. It seemed like a simple fix.

I used a pair of wire cutters to shorten the loop and reconnected it with that ball and chain connector-thingy. I didn’t realize that connector-thingy wouldn’t feed through the roller mechanism. Doh!

Any suggestions for alternatives to this connector thingy? Something that isn’t so bulky and will fit through the feed?