diff --git a/var/spack/repos/builtin/packages/clingo/package.py b/var/spack/repos/builtin/packages/clingo/package.py
index 164260eb731..3747998c776 100644
--- a/var/spack/repos/builtin/packages/clingo/package.py
+++ b/var/spack/repos/builtin/packages/clingo/package.py
@@ -4,6 +4,7 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 from spack import *
+from spack.compiler import UnsupportedCompilerFlag
 
 
 class Clingo(CMakePackage):