diff --git a/src/security/transform/step-source.hpp b/src/security/transform/step-source.hpp
index 76388f7..a017fc6 100644
--- a/src/security/transform/step-source.hpp
+++ b/src/security/transform/step-source.hpp
@@ -68,9 +68,8 @@
    *
    * use write() and end() method explicitly to input data.
    */
-  virtual void
+  void
   doPump() final;
-
 };
 
 typedef StepSource stepSource;