diff --git a/extra/libass/build b/extra/libass/build
index 5478da0e..a30536c2 100755
--- a/extra/libass/build
+++ b/extra/libass/build
@@ -7,9 +7,8 @@ sed -e 's/as_fn_error.*fribidi/: 0 "/' \
     -e '/pkg_requires="fribidi >= .*/d' \
     configure > _
 mv -f _ configure
-chmod +x configure
 
-./configure \
+sh ./configure \
     FRIBIDI_LIBS="  " \
     --prefix=/usr \
     --enable-fontconfig