diff --git a/taiga/mdrender/extensions/mentions.py b/taiga/mdrender/extensions/mentions.py
index 83eeae20..2dcea03a 100644
--- a/taiga/mdrender/extensions/mentions.py
+++ b/taiga/mdrender/extensions/mentions.py
@@ -32,7 +32,7 @@ from taiga.users.models import User
 
 class MentionsExtension(Extension):
     def extendMarkdown(self, md, md_globals):
-        MENTION_RE = r'(@)([a-zA-Z0-9.-\.]+)'
+        MENTION_RE = r'(@)([a-zA-Z0-9.-\._]+)'
         mentionsPattern = MentionsPattern(MENTION_RE)
         mentionsPattern.md = md
         md.inlinePatterns.add('mentions', mentionsPattern, '_end')
diff --git a/tests/integration/test_mdrender.py b/tests/integration/test_mdrender.py
index 91b81ea2..169230db 100644
--- a/tests/integration/test_mdrender.py
+++ b/tests/integration/test_mdrender.py
@@ -38,6 +38,13 @@ def test_proccessor_valid_user_mention():
     assert result == expected_result
 
 
+def test_proccessor_valid_user_mention_with_dashes():
+    factories.UserFactory(username="user1_text_after_dash", full_name="test name")
+    result = render(dummy_project, "**@user1_text_after_dash**")
+    expected_result = "<p><strong><a class=\"mention\" href=\"http://localhost:9001/profile/user1_text_after_dash\" title=\"test name\">@user1_text_after_dash</a></strong></p>"
+    assert result == expected_result
+
+
 def test_proccessor_invalid_user_mention():
     result = render(dummy_project, "**@notvaliduser**")
     assert result == '<p><strong>@notvaliduser</strong></p>'