diff --git a/lib/spack/spack/test/data/config/config.yaml b/lib/spack/spack/test/data/config/config.yaml
index 06112511895..31e5e36bada 100644
--- a/lib/spack/spack/test/data/config/config.yaml
+++ b/lib/spack/spack/test/data/config/config.yaml
@@ -12,3 +12,6 @@ config:
   verify_ssl: true
   checksum: true
   dirty: false
+  module_roots:
+    tcl:    $spack/share/spack/modules
+    lmod:   $spack/share/spack/lmod