Systems and methods to clamp an impeller on a shaft in a centrifugal compressor. The embodiments as disclosed herein may include clamping individual impeller independently to the shaft, which may reduce the tolerance stack-up effect of a plurality of impellers. The impeller can be clamped to the shaft by positioning, for example, a relatively stiff support (e.g. a shaft locknut) on a front side of the impeller. The impeller can also be clamped to the shaft by a relatively flexible support to compensate for e.g. thermal expansion/contraction of the impeller. The embodiments as disclosed herein are particularly suitable for a multi-stage impeller.