diff --git a/dev-lang/gnat-gpl/gnat-gpl-2018.ebuild b/dev-lang/gnat-gpl/gnat-gpl-2018.ebuild
index e2bd431e08350..42cc96779eff5 100644
--- a/dev-lang/gnat-gpl/gnat-gpl-2018.ebuild
+++ b/dev-lang/gnat-gpl/gnat-gpl-2018.ebuild
@@ -37,7 +37,7 @@ SRC_URI+="
 
 LICENSE+=" GPL-2 GPL-3"
 KEYWORDS="~amd64 ~x86"
-IUSE="bootstrap"
+IUSE="+bootstrap"
 
 RDEPEND="!sys-devel/gcc:${GCC_CONFIG_VER}"
 DEPEND="${RDEPEND}