diff --git a/lib/spack/spack/operating_systems/linux_distro.py b/lib/spack/spack/operating_systems/linux_distro.py
index 0e97317b1b2..276235d18b5 100644
--- a/lib/spack/spack/operating_systems/linux_distro.py
+++ b/lib/spack/spack/operating_systems/linux_distro.py
@@ -48,6 +48,11 @@ def __init__(self):
         # grab the first legal identifier in the version field.  On
         # debian you get things like 'wheezy/sid'; sid means unstable.
         # We just record 'wheezy' and don't get quite so detailed.
-        version = re.split(r'[^\w-]', version)[0]
+        version = re.split(r'[^\w-]', version)
+
+        if 'ubuntu' in distname:
+            version = '.'.join(version[0:2])
+        else:
+            version = version[0]
 
         super(LinuxDistro, self).__init__(distname, version)