Gamma-ray spectrometry is a very powerful tool for radioactivity measurements. For accurate gamma-ray spectrometry, certain correction measures should be considered, for instance, systematic uncertainty in the photo-peak efficiency due to the differences between the matrix (density and chemical composition) of the reference and the other bulk samples. Therefore, gamma-ray attenuation correction factors are of major concern for precise gamma-ray spectrometry. Simple practical correction for the photo-peak efficiency, due to discrepancies in both the samples' matrices and densities (self-attenuation), is performed in this study. This study suggests a brief measurement of relative photons transmission through both reference and unknown bulk samples where the variations of photon transmissions are assumed to be linearly correlated to the samples' densities. Specific correction factors would be produced for each analyzed sample to be considered when their activities are calculated. Practically, the suggested method was verified and succeeded in improving the obtained results.