diff --git a/jinja2/parser.py b/jinja2/parser.py
index f2a129c..19ee166 100644
--- a/jinja2/parser.py
+++ b/jinja2/parser.py
@@ -220,6 +220,7 @@
             if args:
                 self.stream.expect('comma')
             arg = self.parse_assign_target(name_only=True)
+            arg.set_ctx('param')
             if self.stream.skip_if('assign'):
                 defaults.append(self.parse_expression())
             args.append(arg)