--- a/old-configure.in
+++ b/old-configure.in
@@ -9012,16 +9012,20 @@ RC=
 # Run the SpiderMonkey 'configure' script.
 dist=$MOZ_BUILD_ROOT/dist
 ac_configure_args="$_SUBDIR_CONFIG_ARGS"
 
 # --with-system-nspr will have been converted into the relevant $NSPR_CFLAGS
 # and $NSPR_LIBS.
 ac_configure_args="`echo $ac_configure_args | sed -e 's/--with-system-nspr\S* *//'`"
 
+# Force the subconfigure to use the js project/application regardless of any
+# --enable-application/--enable-project passed to this configure.
+ac_configure_args="$ac_configure_args --enable-application=js --enable-project=js"
+
 if test "$_INTL_API" = no; then
     ac_configure_args="$ac_configure_args --without-intl-api"
 fi
 
 if test "$BUILD_CTYPES"; then
     # Build js-ctypes on the platforms we can.
     ac_configure_args="$ac_configure_args --enable-ctypes"
 fi