diff --git a/grudge/symbolic/mappers/__init__.py b/grudge/symbolic/mappers/__init__.py
index 745d56be2a0604bc64b26c7d3add125131835480..3441852d0790a2d279b333e115340f7ccd9c1aad 100644
--- a/grudge/symbolic/mappers/__init__.py
+++ b/grudge/symbolic/mappers/__init__.py
@@ -326,7 +326,7 @@ class OperatorBinder(CSECachingMapperMixin, IdentityMapper):
                         % first)
             return sym.OperatorBinding(first, self.rec(prod))
         else:
-            return first * self.rec(flattened_product(expr.children[1:]))
+            return self.rec(first) * self.rec(flattened_product(expr.children[1:]))
 
 # }}}