diff --git a/system/service.py b/system/service.py
index 108427bb954..321950cb73b 100644
--- a/system/service.py
+++ b/system/service.py
@@ -107,6 +107,9 @@ import time
 import string
 
 # The distutils module is not shipped with SUNWPython on Solaris.
+# It's in the SUNWPython-devel package which also contains development files
+# that don't belong on production boxes.  Since our Solaris code doesn't
+# depend on LooseVersion, do not import it on Solaris.
 if platform.system() != 'SunOS':
     from distutils.version import LooseVersion