diff --git a/src/main/entity.cl b/src/main/entity.cl
index c62201f..3b6045f 100644
--- a/src/main/entity.cl
+++ b/src/main/entity.cl
@@ -68,6 +68,7 @@
 (defgeneric stream-entity-length (entity))
 
 (defmethod render-entity-headers :before ((e stream-entity-mixin) stream)
+  (declare (ignore stream))
   (setf (slot-value e 'content-length) (stream-entity-length e)))
 
 (defmethod render-entity-body ((entity stream-entity-mixin) stream)