diff --git a/tiramisu/option/baseoption.py b/tiramisu/option/baseoption.py
index e0bf67f..c8cabd8 100644
--- a/tiramisu/option/baseoption.py
+++ b/tiramisu/option/baseoption.py
@@ -31,7 +31,7 @@ STATIC_TUPLE = frozenset()
 
 
 submulti = 2
-NAME_REGEXP = re.compile(r'^[a-z][a-zA-Z\d_-]*$')
+NAME_REGEXP = re.compile(r'^[a-z1-Z][a-zA-Z\d_-]*$')
 FORBIDDEN_NAMES = frozenset(['iter_all', 'iter_group', 'find', 'find_first',
                              'make_dict', 'unwrap_from_path', 'read_only',
                              'read_write', 'getowner', 'set_contexts'])