The La Liga champions have had a hit-and-miss start to the season under Zinedine Zidane.
Real are second in the table but they already find themselves five points behind rivals Barcelona after just eight games.
And according to Spanish outlet Diario Gol, Ronaldo reckons Real must get a new goalkeeper if they are to improve.
The Portugal international thinks Keylor Navas and Kiko Casilla are not good enough to succeed at the Bernabeu.
And Diario Gol say Ronaldo has a shortlist of keepers in mind.
Manchester United star David De Gea, Chelsea’s Thibaut Courtois and Barcelona stopper Marc Andre ter Stegen would be perfect solutions for the Real talisman.
Diario Gol add that Ronaldo has told Real president Florentino Perez his views.
Reports yesterday claimed United are worried their pursuit of Real star Gareth Bale could cost them De Gea.
Real are said to want the Spain international involved in any deal that sends Bale to Old Trafford next summer.
Jose Mourinho is a huge admirer of the former Tottenham star and he publicly revealed his desire to land Bale earlier this year.