Croatia coach Zlatko Kranjcar admitted his side's defending needs to improve after they lost their final World Cup warm-up game against Spain 2-1 in Geneva on Wednesday.

Croatia were gifted the opener when Pablo Ibanez headed into his own goal after just 14 minutes, but they were unable to hold on to the lead when Spain stepped up the pressure in the second half.

Mariano Pernia's free-kick made it 1-1 just after the hour and Fernando Torres secured victory in stoppage-time with an impressive solo goal.

Croatia face Brazil in their World Cup opener on June 13 and Kranjcar knows the holders' fearsome strike-force would thrive on the defensive errors his side made against Spain.

"It was a good game but it all changed when Spain managed to get the equaliser," he said.

"We will improve in defence and we'll be ready for the World Cup."