The present disclosure relates to a tensioning device of a strapping device for strapping packaged material with a strap. The tensioning device includes a tensioning wheel operatively connectable to a drive device to rotate the tensioning wheel about a rotational axis. The tensioning wheel has a circumferential surface configured to engage the strap. The tensioning device also includes a movable spacer provided on the tensioning wheel in the region of the circumferential surface of the tensioning wheel. The spacer is movable between a first position in which part of the spacer is a first distance from the rotational axis and a second position in which the part of the spacer is a second different distance from the rotational axis. The spacer projects beyond the circumferential surface of the tensioning wheel in at least one of the positions.