The present invention relates to a plant of the species Solanum lycopersicum comprising in its genome at least one copy of a mutant allele of the wild type ACO4 gene, wherein said mutant allele when present in homozygous form causes the fruits having an increased fruit firmness after the fruits entered the full red stage. The present invention further relates to a seed from which a plant according to present invention can be grown, a plant grown from the seed according to the present invention, a fruit produced by a plant according to the present invention and a part of a plant according to the present invention. The present invention further relates to a method for producing tomato fruit having an increased shelf life comprising growing a plant according to the present invention. The present invention further relates to a method of identifying and/or selecting a plant or plant part according to the present invention. The present invention further relates to a method of producing a plant of the species Solanum lycopersicum comprising in its genome at least one copy of a mutant allele of the ACO4 gene according to the present invention. The present invention further relates to the use of a plant of the species Solanum lycopersicum of the present invention for consumption or as a source of propagation material.