diff --git a/grudge/function_registry.py b/grudge/function_registry.py
index 6efa39da38a8bb30aead074ac7d96856ec70fc33..df709f93e7ab13fd180d91cca0cce30735ae8f87 100644
--- a/grudge/function_registry.py
+++ b/grudge/function_registry.py
@@ -71,12 +71,9 @@ class CElementwiseUnaryFunction(Function):
         assert len(arg_dds) == 1
         return arg_dds[0]
 
-    def __call__(self, queue, *args):
-        assert len(args) == 1
-
+    def __call__(self, queue, arg):
         func_name = self.identifier
 
-        arg, = args
         from numbers import Number
         if (
                 isinstance(arg, Number)
diff --git a/grudge/symbolic/mappers/__init__.py b/grudge/symbolic/mappers/__init__.py
index 8266db938bdb89bc2dde0bce52b96c55474de9b2..0e9b8e02d67b6f2b86d217d8c230263281d49a19 100644
--- a/grudge/symbolic/mappers/__init__.py
+++ b/grudge/symbolic/mappers/__init__.py
@@ -844,7 +844,7 @@ class StringifyMapper(pymbolic.mapper.stringifier.StringifyMapper):
         return "%s:%s" % (expr.name, self._format_dd(expr.dd))
 
     def map_function_symbol(self, expr, enclosing_prec):
-        return expr
+        return expr.name
 
     def map_interpolation(self, expr, enclosing_prec):
         return "Interp" + self._format_op_dd(expr)