Transfering etfs from a market account to TFSA without going over the contribution limit?

I have a market account in Questrade and would like to transfer $5,000 worth of ETFs from the market account to the TFSA.

Last time I did it, I specified the number of shares I wanted to send from one to the other. But, because of fluctuations in the share price over the couple of days it took to process, by the time it landed in my TFSA, I was over my contribution limit and had to sell some.

So do I go about it? Do I have to sell the shares and transfer it in cash? Should i just save money and contribute a little at a time?