diff --git a/src/security/transform/stream-source.hpp b/src/security/transform/stream-source.hpp
index b818fe7..5dcefdd 100644
--- a/src/security/transform/stream-source.hpp
+++ b/src/security/transform/stream-source.hpp
@@ -49,7 +49,7 @@
   /**
    * @brief Read bytes from the input stream until EOF is reached and write them into the next module.
    */
-  virtual void
+  void
   doPump() final;
 
 public: