diff --git a/firefox.be0 b/firefox.be0
index 062ef3e25..8c53b5456 100755
--- a/firefox.be0
+++ b/firefox.be0
@@ -19,7 +19,7 @@ mee_configure() {
     . /pkg/rustc-1.61.0-0/profile
 
     cat > ${S}/mozconfig <<-EOF
-	ac_add_options --prefix=/usr
+	ac_add_options --prefix="${PREFIX}"
 	ac_add_options --enable-application=browser
 	ac_add_options --disable-necko-wifi
 	ac_add_options --enable-official-branding