diff --git a/lib/noosfero.rb b/lib/noosfero.rb
index 5081ffa..348d872 100644
--- a/lib/noosfero.rb
+++ b/lib/noosfero.rb
@@ -18,7 +18,7 @@ module Noosfero
   end
 
   def self.identifier_format
-    '[a-z][a-z0-9~.]*([_-][a-z0-9~.]+)*'
+    '[a-z0-9][a-z0-9~.]*([_-][a-z0-9~.]+)*'
   end
 
   private
diff --git a/test/unit/noosfero_test.rb b/test/unit/noosfero_test.rb
index 62ca33e..1987ff3 100644
--- a/test/unit/noosfero_test.rb
+++ b/test/unit/noosfero_test.rb
@@ -26,7 +26,6 @@ class NoosferoTest < Test::Unit::TestCase
   should 'identifier format' do
     assert_match /^#{Noosfero.identifier_format}$/, 'bli-bla'
     assert_no_match /^#{Noosfero.identifier_format}$/, 'UPPER'
-    assert_no_match /^#{Noosfero.identifier_format}$/, '129812startingwithnumber'
     assert_match /^#{Noosfero.identifier_format}$/, 'with~tilde'
     assert_match /^#{Noosfero.identifier_format}$/, 'with.dot'
   end
@@ -46,4 +45,8 @@ class NoosferoTest < Test::Unit::TestCase
     assert_equal({:port => 9999}, Noosfero.url_options)
   end
 
+  should 'allow identifier starting with number' do
+    assert_match /^#{Noosfero.identifier_format}$/, '129812startingwithnumber'
+  end
+
 end
--
libgit2 0.21.2