diff --git a/var/spack/repos/builtin/packages/singularityce/package.py b/var/spack/repos/builtin/packages/singularityce/package.py
index 82374ac5b75..11a04285aa2 100644
--- a/var/spack/repos/builtin/packages/singularityce/package.py
+++ b/var/spack/repos/builtin/packages/singularityce/package.py
@@ -80,7 +80,7 @@ def config_options(self):
     def edit(self, spec, prefix):
         with working_dir(self.build_directory):
             confstring = "./mconfig --prefix=%s" % prefix
-            confstring += " ".join(config_options)
+            confstring += " " + " ".join(self.config_options)
             if "~suid" in spec:
                 confstring += " --without-suid"
             if "~network" in spec: