Update environment.py
diff --git a/jinja2/environment.py b/jinja2/environment.py
index 468ccc0..5055ed3 100644
--- a/jinja2/environment.py
+++ b/jinja2/environment.py
@@ -757,7 +757,7 @@
     def _load_template(self, name, globals):
         if self.loader is None:
             raise TypeError('no loader for this environment specified')
-        # use abs path for cache
+        # use abs path for cache key
         cache_key = self.loader.get_source(self, name)[1]
         if self.cache is not None:
             template = self.cache.get(cache_key)