Boss Neil Lennon urged his shot-shy players to turn chances into goals following their 2-0 Clydesdale Bank Premier League win over bottom side Dundee at Parkhead.
Strikes by Gary Hooper and Victor Wanyama gave the home side three welcome points but the victory would have been more comprehensive had it not been for former Hoops goalkeeper Robert Douglas and some poor finishing.
The 40-year-old Dees number one had a fine match, brilliantly saving a Scott Brown penalty in the 38th minute - only to be beaten just before the break when Hooper hammered in from 10 yards.
The Celtic boss, asked about the missed chances, replied: "It is a concern for me."
He added: "What isn't a concern is the chances we are creating because we are doing that on numerous occasions in games - but I would like to see us start putting a few more away."
Lennon joked about the performance of former Celtic team mate Douglas.
He smiled: "I will have him by the neck later on for making my day uncomfortable.
"I thought he was excellent. It took two quality goals to beat him."
Dundee boss Barry Smith paid tribute to Douglas, saying: "Rab has done extremely well for us all season.
"He gets a lot of plaudits and maybe a lot of people give him some stick but at 40 years of age, producing performances week in, week out is difficult."