diff --git a/lib/spack/spack/test/module_parsing.py b/lib/spack/spack/test/module_parsing.py
index 1e1c3a993b6142fe12b8c1851d68a4ade48afa29..fc8111408f7210a10fb03998d0916ee8b7951c79 100644
--- a/lib/spack/spack/test/module_parsing.py
+++ b/lib/spack/spack/test/module_parsing.py
@@ -15,7 +15,10 @@
     ModuleError)
 
 
+env = os.environ.copy()
+env['LC_ALL'] = 'C'
 typeset_func = subprocess.Popen('module avail',
+                                env=env,
                                 stdout=subprocess.PIPE,
                                 stderr=subprocess.PIPE,
                                 shell=True)