diff --git a/tests/unit/util/simple-notification.hpp b/tests/unit/util/simple-notification.hpp
index acfa172..ece2c48 100644
--- a/tests/unit/util/simple-notification.hpp
+++ b/tests/unit/util/simple-notification.hpp
@@ -59,8 +59,7 @@
   void
   wireDecode(const Block& block)
   {
-    m_message.assign(reinterpret_cast<const char*>(block.value()),
-                     block.value_size());
+    m_message = readString(block);
 
     // error for testing
     if (!m_message.empty() && m_message[0] == '\x07')