diff --git a/native/cpp/CommonCpp/CryptoTools/Session.cpp b/native/cpp/CommonCpp/CryptoTools/Session.cpp
--- a/native/cpp/CommonCpp/CryptoTools/Session.cpp
+++ b/native/cpp/CommonCpp/CryptoTools/Session.cpp
@@ -154,7 +154,7 @@
         ". Hash: " +
         std::string{messageHashBuffer.begin(), messageHashBuffer.end()}};
   }
-  return std::string{(char *)decryptedMessage.data(), decryptedSize};
+  return std::string{decryptedMessage.begin(), decryptedMessage.end()};
 }
 
 std::string Session::decryptSequential(EncryptedData &encryptedData) {
@@ -199,7 +199,7 @@
         std::string{::olm_session_last_error(session)} + ". Hash: " +
         std::string{messageHashBuffer.begin(), messageHashBuffer.end()}};
   }
-  return std::string{(char *)decryptedMessage.data(), decryptedSize};
+  return std::string{decryptedMessage.begin(), decryptedMessage.end()};
 }
 
 int Session::getVersion() {