In general, spiders that build long-lasting webs invest a larger amount of silk and consequently a larger amount of energy in their construction than those species that build ephemeral webs. It is expected that spiders that build long-lasting webs choose rigid substrates for web construction to help preserve their investment. I experimentally tested this prediction by confining Cyrtophora citricola (Forsskål 1775) (Coddington 1989) spiders (n  =  32) in containers provided with firm and unstable substrates for the spiders to construct their webs. This experiment confirms that C. citricola strongly prefers firm substrates to which to attach its web when it must choose between a firm and an unstable substrate.