The article deals with A. Kibovskyʼs atributation of the portrait of M.L. Dubelt. A version is proposed about the possible author of the portrait, stored in the State Hermitage. Based on M.L. Dubeltʼs recollections held at the Russian State Military Historical Archive, it can be assumed that the author of the portrait was not G.G. Gagarin, as previously thought, but V.F. Timm, whom Dubelt met in the autumn of 1849.