Straight men express more negative attitudes toward feminine, rather than masculine gay men, a phenomenon we label the gay-gender expression effect (GGEE). This effect stems partly from men's motivation to conform to the antifemininity norm of masculinity. This study investigated whether perceived changes in men's gender roles moderates this effect. Straight male participants (N 166) read information that (a) gay men's gender expression is either feminine or masculine, and that (b) men's gender role in society is either remaining masculine or becoming more feminine. They then reported their attitudes toward gay people. Results showed that the GGEE appears in the condition where men remain masculine, but fades away in the condition where men are becoming feminine. Specifically, we observed negative attitudes toward gay people regardless of their gender expression when gay men are portrayed as masculine and men's gender role in society is evolving (becoming more feminine). This effect was observed among participants who most strongly endorse the traditional antifemininity norm of masculinity. Implications of changes in gender norms are discussed.