diff --git a/src/wscript b/src/wscript
index dbcb6018a..5e646ab9e 100644
--- a/src/wscript
+++ b/src/wscript
@@ -119,7 +119,7 @@ def create_ns3_module(bld, name, dependencies=(), test=False):
 
     module.is_ns3_module = True
     module.name = 'ns3-' + name
-    module.vnum = wutils.VERSION
+    module.vnum = wutils.VNUM
     # Add the proper path to the module's name.
     module.target = '%s/ns3-%s' % (bld.srcnode.relpath_gen(bld.path), name)
     # Set the libraries this module depends on.  
diff --git a/wscript b/wscript
index 023838f62..2f9644ee3 100644
--- a/wscript
+++ b/wscript
@@ -67,6 +67,11 @@ APPNAME = 'ns'
 wutils.VERSION = VERSION
 wutils.APPNAME = APPNAME
 
+if re.match(r"\d+\.\d+(\.\d+)?", VERSION) is not None:
+    wutils.VNUM = VERSION
+else:
+    wutils.VNUM = None
+
 # these variables are mandatory ('/' are converted automatically)
 srcdir = '.'
 blddir = 'build'