Closes #1069: look up plugin lexer aliases like regular: lowercased

1 files changed, 1 insertions, 1 deletions

diff --git a/pygments/lexers/__init__.py b/pygments/lexers/__init__.py
index 333ff630..7d0b89d4 100644
--- a/pygments/lexers/__init__.py
+++ b/pygments/lexers/__init__.py
@@ -88,7 +88,7 @@ def get_lexer_by_name(_alias, **options):
             return _lexer_cache[name](**options)
     # continue with lexers from setuptools entrypoints
     for cls in find_plugin_lexers():
-        if _alias in cls.aliases:
+        if _alias.lower() in cls.aliases:
             return cls(**options)
     raise ClassNotFound('no lexer for alias %r found' % _alias)