Prior to 1998, shrinkwrap licenses were valid in Singapore. However, the following parts of the Copyright Act were deleted by the Copyright (Amendment) Act 1998:

Deleted:
Section 39(2)

    (b) contrary to an express direction by or on behalf of the owner of the
    copyright in the computer program given to the owner of the original copy
    not later than the time when the owner of the original copy acquired the
    original copy.

Deleted:    
Section 39(4)
    
    For the purposes of this section -
    
    (a) a reference to a copy of a computer program or of an adaptation of a
    computer program is a reference to any article in which the computer program
    or adaptation is reproduced in a material form; and
    
    (b) a reference to express direction, in relation to a copy of a computer
    program or of an adaptation of a computer program, includes a reference to
    a clearly legible direction printed on the copy or on a package in which
    the copy is supplied.
    

Taken together with the new subsection (4), the effect of these changes was to make invalid any terms in a shrinkwrap license which prohibited the making of backup copies.