diff --git a/pym/cl_opt.py b/pym/cl_opt.py
index 0a9bc3e..ec430c5 100644
--- a/pym/cl_opt.py
+++ b/pym/cl_opt.py
@@ -297,7 +297,7 @@ class opt(optparse.OptionParser):
 
     def checkVarSyntax(self,values):
         """Check value of parameter set, was used for change vars"""
-        reCheckSet = re.compile("^([a-z_]+=[^,]+)(,\s*[a-z_]+=[^,]+)*$")
+        reCheckSet = re.compile("^[a-z0-9_]+=[^,]+(,[a-z0-9_]+=[^,]+)*$")
         if values.set:
             for val in values.set:
                 if not reCheckSet.match(val):