diff --git a/var/spack/repos/builtin/packages/python/package.py b/var/spack/repos/builtin/packages/python/package.py
index 3e18c294aaa9187af2231bd492e04fdfcc55e532..13e26f02601b4e9aea56b7cd074713659edd2dbd 100644
--- a/var/spack/repos/builtin/packages/python/package.py
+++ b/var/spack/repos/builtin/packages/python/package.py
@@ -396,7 +396,8 @@ def filter_compilers(self):
         ]
 
         filter_file(spack_cc,  self.compiler.cc,  *filenames, **kwargs)
-        filter_file(spack_cxx, self.compiler.cxx, *filenames, **kwargs)
+        if spack_cxx and self.compiler.cxx:
+            filter_file(spack_cxx, self.compiler.cxx, *filenames, **kwargs)
 
     @run_after('install')
     def symlink(self):