diff --git a/setup.py b/setup.py
index <HASH>..<HASH> 100644
--- a/setup.py
+++ b/setup.py
@@ -105,11 +105,14 @@ if not ISRELEASED:
             # partial clone, manually construct version string
             # this is the format before we started using git-describe
             # to get an ordering on dev version strings.
-            rev = "v%s.dev-%s" % (VERSION, rev)
+            rev = "v%s+dev.%s" % (VERSION, rev)
 
         # Strip leading v from tags format "vx.y.z" to get th version string
         FULLVERSION = rev.lstrip('v')
 
+        # make sure we respect PEP 440
+        FULLVERSION = FULLVERSION.replace("-", "+dev", 1).replace("-", ".")
+
 else:
     FULLVERSION += QUALIFIER
Respect PEP <I> (#<I>)

* Respect PEP <I>



Change unreleased version numbers as to respect PEP <I>.  Rather than

`<I>-9-g<I>a1a<I>` we will have `<I>+dev9.g<I>a1a<I>`.  This means

automated setuptools requirements can be respected.  Closes #<I>.



* The fallback version string should also respect PEP <I>