diff --git a/src/security/transform/base64-encode.cpp b/src/security/transform/base64-encode.cpp
index 0a27bed..60bc25f 100644
--- a/src/security/transform/base64-encode.cpp
+++ b/src/security/transform/base64-encode.cpp
@@ -44,7 +44,7 @@
 
   ~Impl()
   {
-    BIO_free_all(m_sink);
+    BIO_free_all(m_base64);
   }
 
 public: