Lighting device for illuminating interiors in buildings or outdoor installations, wherein the lighting device is configured for mounting in a substantially right-angled corner region of the interior, of the outdoor installation or of some other object, having the following features: a) a luminaire holder configured for securing in the substantially right-angled corner region , wherein the luminaire holder has at least a first securing surface for securing to a first corner region surface and a second securing surface for securing to a second corner region surface , wherein the first and second securing surfaces of the luminaire holder are arranged substantially at right angles to one another, b) a luminaire cover composed of at least partly light-transmissive material, wherein the luminaire cover is configured for securing to the luminaire holder , c) wherein a receptacle space for receiving at least one illuminant of the lighting device, in particular an LED strip, is formed by an interspace between the luminaire holder and the luminaire cover , characterized in that the lighting device furthermore has a first wing , at which the first securing surface is formed, and a second wing, at which the second securing surface is formed, wherein the wings are connected to one another by way of a connecting section and wherein a) the first wing has a first base section , which is adjacent to the first securing surface towards the second wing , wherein the first securing surface is angled relative to the first base section by an acute angle (α 1 ), in particular an angle in the range of 1 degree to 8 degrees, and/or b) the second wing has a second base section , which is adjacent to the second securing surface towards the first wing , wherein the second securing surface is angled relative to the second base section by an acute angle (α 2 ), in particular an angle in the range of 1 degree to 8 degrees. a) a luminaire holder configured for securing in the substantially right-angled corner region , wherein the luminaire holder has at least a first securing surface for securing to a first corner region surface and a second securing surface for securing to a second corner region surface , wherein the first and second securing surfaces of the luminaire holder are arranged substantially at right angles to one another, b) a luminaire cover composed of at least partly light-transmissive material, wherein the luminaire cover is configured for securing to the luminaire holder , c) wherein a receptacle space for receiving at least one illuminant of the lighting device, in particular an LED strip, is formed by an interspace between the luminaire holder and the luminaire cover , a) the first wing has a first base section , which is adjacent to the first securing surface towards the second wing , wherein the first securing surface is angled relative to the first base section by an acute angle (α 1 ), in particular an angle in the range of 1 degree to 8 degrees, and/or b) the second wing has a second base section , which is adjacent to the second securing surface towards the first wing , wherein the second securing surface is angled relative to the second base section by an acute angle (α 2 ), in particular an angle in the range of 1 degree to 8 degrees. <EOS>