diff --git a/lib/spack/spack/modules/common.py b/lib/spack/spack/modules/common.py
index e16e366cb0..62df108b50 100644
--- a/lib/spack/spack/modules/common.py
+++ b/lib/spack/spack/modules/common.py
@@ -64,7 +64,7 @@
     'compiler',
     'compiler.name',
     'compiler.version',
-    'architecture'
+    'architecture',
     # tokens from old-style format strings
     'package',
     'compilername',