diff --git a/games-strategy/0ad/0ad-9999.ebuild b/games-strategy/0ad/0ad-9999.ebuild
index 3ec051e..f2ab2b1 100644
--- a/games-strategy/0ad/0ad-9999.ebuild
+++ b/games-strategy/0ad/0ad-9999.ebuild
@@ -56,7 +56,7 @@ src_configure() {
 
 	./update-workspaces.sh \
 		--with-system-nvtt \
-		--with-system-mozjs31 \
+		--with-system-mozjs24 \
 		$(usex pch "" "--without-pch") \
 		$(usex test "" "--without-tests") \
 		$(usex audio "" "--without-audio") \