Barrier-coated cellulose-based substrate, for use as a gas barrier sheet in a laminated packaging material for oxygen-sensitive products, comprising a cellulose-based substrate having a density of at least 900 kg/m 3, and a grammage from 30 to 80 g/m 2, and applied on a first side of the cellulose-based substrate, at least one gas barrier coating (13a, 14a) of at least one gas barrier material to a total thickness from 2 to 7000 nm, such as from 2 to 5000 nm, such as from 2 to 4000 nm, the gas barrier material excluding nanocrystalline cellulose, NCC, wherein the barrier-coated cellulose-based substrate comprises a ductile base layer pre-coating, which is applied by means of dispersion coating and subsequent drying, onto the surface of the first side of the cellulose-based substrate and positioned beneath the at least one gas barrier coating (13a, 14a), wherein the at least one gas barrier coating (13a, 14a) comprises a barrier dispersion coating, first applied by means of dispersion or solution coating onto the ductile base layer pre-coating, and a barrier deposition coating, subsequently applied by means of a vapour deposition method, onto the barrier dispersion coating, the barrier dispersion coating being applied at a total amount from 0.2 to 5 g/m 2, dry weight, the barrier deposition coating being a vapour deposition coating of a material selected from metals, metal oxides, inorganic oxides and carbon coatings, and being applied at a thickness from 5 to 200 nm, the ductile base layer pre-coating being obtained from an aqueous latex composition, such as a latex selected from the group comprising styrene-butadiene latex (SB-latex), methylstyrene-butadiene latex, styrene acrylate latex (SA-latex), acrylate latex, such as vinyl acrylic copolymers and vinyl acetate acrylate latex, styrene-butadiene-acrylonitrile latex, styrene-acrylate-acrylonitrile latex, styrene-butadiene-acrylate-acrylonitrile latex, styrene-maleic anhydride latex, styrene-acrylate-maleic anhydride latex, mixtures thereof, or bio-based latex made with plant-based polymer materials, the plant-based polymer materials being selected from the group comprising starch derivatives, including modified starches and crosslinked starches, polyisoprene, lignin-based polymers, alginates and gums, such as guar gum, and soy-based proteins, and is applied at a grammage from 2 to 15 g/m 2, dry weight, the barrier-coated cellulose-based substrate thus being suitable for providing gas barrier properties in a laminated packaging material and in packages made thereof. a cellulose-based substrate having a density of at least 900 kg/m 3, and a grammage from 30 to 80 g/m 2, and applied on a first side of the cellulose-based substrate, at least one gas barrier coating (13a, 14a) of at least one gas barrier material to a total thickness from 2 to 7000 nm, such as from 2 to 5000 nm, such as from 2 to 4000 nm, the gas barrier material excluding nanocrystalline cellulose, NCC, wherein the barrier-coated cellulose-based substrate comprises a ductile base layer pre-coating, which is applied by means of dispersion coating and subsequent drying, onto the surface of the first side of the cellulose-based substrate and positioned beneath the at least one gas barrier coating (13a, 14a), wherein the at least one gas barrier coating (13a, 14a) comprises a barrier dispersion coating, first applied by means of dispersion or solution coating onto the ductile base layer pre-coating, and a barrier deposition coating, subsequently applied by means of a vapour deposition method, onto the barrier dispersion coating, the barrier dispersion coating being applied at a total amount from 0.2 to 5 g/m 2, dry weight, the barrier deposition coating being a vapour deposition coating of a material selected from metals, metal oxides, inorganic oxides and carbon coatings, and being applied at a thickness from 5 to 200 nm, the ductile base layer pre-coating being obtained from an aqueous latex composition, such as a latex selected from the group comprising styrene-butadiene latex (SB-latex), methylstyrene-butadiene latex, styrene acrylate latex (SA-latex), acrylate latex, such as vinyl acrylic copolymers and vinyl acetate acrylate latex, styrene-butadiene-acrylonitrile latex, styrene-acrylate-acrylonitrile latex, styrene-butadiene-acrylate-acrylonitrile latex, styrene-maleic anhydride latex, styrene-acrylate-maleic anhydride latex, mixtures thereof, or bio-based latex made with plant-based polymer materials, the plant-based polymer materials being selected from the group comprising starch derivatives, including modified starches and crosslinked starches, polyisoprene, lignin-based polymers, alginates and gums, such as guar gum, and soy-based proteins, and is applied at a grammage from 2 to 15 g/m 2, dry weight, the barrier-coated cellulose-based substrate thus being suitable for providing gas barrier properties in a laminated packaging material and in packages made thereof.